* macosx/tclMacOSXNotify.c (Tcl_InitNotifier, Tcl_WaitForEvent): create

	notifier thread lazily upon first call to Tcl_WaitForEvent() rather than
	in Tcl_InitNotifier(). Allows calling exeve() in processes where the
	event loop has not yet been run (Darwin's execve() fails in processes
	with more than one thread), in particular allows embedders to call
	fork() followed by execve(), previously the pthread_atfork() child
	handler's call to Tcl_InitNotifier() would immediately recreate the
	notifier thread in the child after a fork.

	* macosx/tclMacOSXFCmd.c (TclMacOSXCopyFileAttributes):    add support
	* macosx/tclMacOSXNotify.c (Tcl_InitNotifier):             for weakly
	* unix/tclUnixInit.c (Tcl_GetEncodingNameFromEnvironment): importing
	symbols not available on OSX 10.2 or 10.3, enables binaires built on
	later OSX versions to run on earlier ones.
	* macosx/Tcl.xcodeproj/project.pbxproj: enable weak-linking; turn on
	                                        extra warnings.
	* macosx/README: document how to enable weak-linking; cleanup.
	* unix/tclUnixPort.h: add support for weak-linking; conditionalize
	AvailabilityMacros.h inclusion; only disable realpath on 10.2 or earlier
	when threads are enabled.
	* unix/tclLoadDyld.c (TclpLoadMemoryGetBuffer): change runtime Darwin
	* unix/tclUnixInit.c (TclpInitPlatform):        release check to use
	                                                global initialized once.
	* unix/tclUnixFCmd.c (DoRenameFile, TclpObjNormalizePath): add runtime
	Darwin release check to determine if realpath is threadsafe.
	* unix/configure.in: add check on Darwin for compiler support of weak
	* unix/tcl.m4:       import and for AvailabilityMacros.h header;
	move Darwin specific checks & defines that are only relevant to the tcl
	build out of tcl.m4; restrict framework option to Darwin; cleanup
	quoting and help messages.
	* unix/configure: autoconf-2.59
	* unix/tclConfig.h.in: autoheader-2.59

	* unix/tclLoadDyld.c (TclpLoadMemory): fix signed-with-unsigned
	comparison and other warnings from gcc4 -Wextra.

13 files changed, 1419 insertions, 1009 deletions

diff --git a/ChangeLog b/ChangeLog
index 2b3437a..3f6a0f1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,51 @@
+2006-07-20   Daniel Steffen  <das@users.sourceforge.net>
+
+	* macosx/tclMacOSXNotify.c (Tcl_InitNotifier, Tcl_WaitForEvent): create
+	notifier thread lazily upon first call to Tcl_WaitForEvent() rather than
+	in Tcl_InitNotifier(). Allows calling exeve() in processes where the
+	event loop has not yet been run (Darwin's execve() fails in processes
+	with more than one thread), in particular allows embedders to call
+	fork() followed by execve(), previously the pthread_atfork() child
+	handler's call to Tcl_InitNotifier() would immediately recreate the
+	notifier thread in the child after a fork.
+
+	* macosx/tclMacOSXFCmd.c (TclMacOSXCopyFileAttributes):    add support
+	* macosx/tclMacOSXNotify.c (Tcl_InitNotifier):             for weakly
+	* unix/tclUnixInit.c (Tcl_GetEncodingNameFromEnvironment): importing
+	symbols not available on OSX 10.2 or 10.3, enables binaires built on
+	later OSX versions to run on earlier ones.
+	* macosx/Tcl.xcodeproj/project.pbxproj: enable weak-linking; turn on
+	                                        extra warnings.
+	* macosx/README: document how to enable weak-linking; cleanup.
+	* unix/tclUnixPort.h: add support for weak-linking; conditionalize
+	AvailabilityMacros.h inclusion; only disable realpath on 10.2 or earlier
+	when threads are enabled.
+	* unix/tclLoadDyld.c (TclpLoadMemoryGetBuffer): change runtime Darwin
+	* unix/tclUnixInit.c (TclpInitPlatform):        release check to use
+	                                                global initialized once.
+	* unix/tclUnixFCmd.c (DoRenameFile, TclpObjNormalizePath): add runtime
+	Darwin release check to determine if realpath is threadsafe.
+	* unix/configure.in: add check on Darwin for compiler support of weak
+	* unix/tcl.m4:       import and for AvailabilityMacros.h header;
+	move Darwin specific checks & defines that are only relevant to the tcl
+	build out of tcl.m4; restrict framework option to Darwin; cleanup
+	quoting and help messages.
+	* unix/configure: autoconf-2.59
+	* unix/tclConfig.h.in: autoheader-2.59
+
+	* generic/regc_locale.c (cclass):
+	* generic/tclExecute.c (TclExecuteByteCode):
+	* generic/tclIOCmd.c (Tcl_ExecObjCmd):
+	* generic/tclListObj.c (NewListIntRep):
+	* generic/tclObj.c (Tcl_GetLongFromObj, Tcl_GetWideIntFromObj,
+	                    FreeBignum, Tcl_SetBignumObj):
+	* generic/tclParseExpr.c (Tcl_ParseExpr):
+	* generic/tclStrToD.c (TclParseNumber):
+	* generic/tclStringObj.c (TclAppendFormattedObjs):
+	* unix/tclLoadDyld.c (TclpLoadMemory):
+	* unix/tclUnixPipe.c (TclpCreateProcess): fix signed-with-unsigned
+	comparison and other warnings from gcc4 -Wextra.
+
 2006-07-13  Andreas Kupries <andreask@activestate.com>
 
 	* unix/tclUnixPort.h: Added the inclusion of
diff --git a/macosx/README b/macosx/README
index 561c468..6c2c81a 100644
--- a/macosx/README
+++ b/macosx/README
@@ -1,7 +1,7 @@
 Tcl Mac OS X README 
 -----------------
 
-RCS: @(#) $Id: README,v 1.6 2005/11/27 02:33:49 das Exp $
+RCS: @(#) $Id: README,v 1.7 2006/07/20 06:18:37 das Exp $
 
 This is the README file for the Mac OS X/Darwin version of Tcl.
 
@@ -36,9 +36,12 @@ Mac OS X specific bugs should usually be assigned to 'das' or 'wolfsuit'.
 - At a minimum, Mac OS X 10.1 is required to run Tcl, but OS X 10.3 or higher is
 recommended (certain [file] operations behave incorrectly on earlier releases).
 
-- Tcl built on Mac OS X 10.x will not run on 10.y for y < x, on the other hand
-Tcl built on 10.y will run on 10.x for y < x (but without any of the fixes and
-optimizations that would be available in a binary built on 10.x).
+- Unless weak-linking is used, Tcl built on Mac OS X 10.x will not run on 10.y
+with y < x; on the other hand Tcl built on 10.y will always run on 10.x with
+y <= x (but without any of the fixes and optimizations that would be available
+in a binary built on 10.x).
+Weak-linking is available on OS X 10.2 or later, it additionally allows Tcl
+built on 10.x to run on any 10.y with x > y >= z (for a chosen z >= 2).
 
 - Tcl extensions can be installed in any of:
 	$HOME/Library/Tcl /Library/Tcl /Network/Library/Tcl /System/Library/Tcl
@@ -79,10 +82,9 @@ http://connect.apple.com (after you register for free ADC membership).
 (see below for details), but can also be built with the standard unix configure
 and make buildsystem in tcl/unix as on any other unix platform (indeed, the
 GNUmakefile is just a wrapper around the unix buildsystem).
-The Mac OS X specifc configure flags are --enable-framework and
+The Mac OS X specific configure flags are --enable-framework and
 --disable-corefoundation (which disables CF and notably reverts to the standard
-select based notifier, you will only need this if your require use of naked fork
-(i.e. not followed by execve) in an unthreaded core).
+select based notifier).
 
 - It is also possible to build with Apple's IDE via the projects in tcl/macosx,
 take care to only use the project matching your DevTools and OS version:
@@ -116,12 +118,22 @@ Notes about the native targets of the Xcode projects:
     export CFLAGS="-arch ppc -arch ppc64 -arch i386 \
 	-isysroot /Developer/SDKs/MacOSX10.4u.sdk -mmacosx-version-min=10.4"
 This requires Mac OS X 10.4 and Xcode 2.2 (_not_ Xcode 2.1) and will work on any
-of the architectures (on i386 DTKs, the -isysroot is not required). Note that it
-is not possible to configure correctly if the current architecture is not
+of the architectures (on intel Macs, the -isysroot is not required). Note that
+it is not possible to configure correctly if the current architecture is not
 present in CFLAGS (i.e. -arch `arch` must always be there). Universal builds of
 Tcl TEA extensions are also possible with CFLAGS set as above, they will be
 [load]able by universal as well as thin binaries of Tcl.
 
+- To enable weak-linking, set the MACOSX_DEPLOYMENT_TARGET environment variable
+to the minimal OS version (>= 10.2) the binaries should be able to run on, e.g:
+    export MACOSX_DEPLOYMENT_TARGET=10.2
+This requires Mac OS X 10.2 and gcc 3.1; if you have gcc 4 or later you can set
+CFLAGS instead:
+    export CFLAGS="-mmacosx-version-min=10.2"
+The Tcl.xcodeproj is setup to produce binaires that can run on 10.2 or later,
+except for the 'ReleaseUniversal'configuration, where they require 10.4.
+Support for weak-linking was added to the code for 8.4.14/8.5a5.
+
 Detailed Instructions for building with macosx/GNUmakefile
 ----------------------------------------------------------
 
@@ -152,8 +164,8 @@ instead by passing an INSTALL_ROOT argument to make:
 - The default Makefile targets will build _both_ debug and optimized versions of
 the Tcl framework with the standard convention of naming the debug library
 Tcl.framework/Tcl_debug.
-This allows you to dynamically link to the debug libraries at runtime by setting
-	setenv DYLD_IMAGE_SUFFIX _debug
+This allows switching to the debug libraries at runtime by setting
+	export DYLD_IMAGE_SUFFIX=_debug
 (c.f. man dyld for more details)
 
 If you only want to build and install the debug or optimized build, use the
diff --git a/macosx/Tcl.xcodeproj/project.pbxproj b/macosx/Tcl.xcodeproj/project.pbxproj
index 89c24e1..9c72230 100644
--- a/macosx/Tcl.xcodeproj/project.pbxproj
+++ b/macosx/Tcl.xcodeproj/project.pbxproj
@@ -1871,7 +1871,7 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/bash;
-			shellScript = "## tcl configure shell script phase\n\ncd \"${TCL_SRCROOT}\"/macosx &&\nif [ configure.ac -nt configure -o ../unix/configure.in -nt configure -o ../unix/tcl.m4 -nt configure -o ../unix/aclocal.m4 -nt configure ]; then\n    echo \"Running autoconf & autoheader in tcl/macosx\"\n    rm -rf autom4te.cache\n    ${AUTOCONF:-/usr/bin/autoconf} && ${AUTOHEADER:-/usr/bin/autoheader}\n    rm -rf autom4te.cache\nfi\n\ncd \"${DERIVED_FILE_DIR}\" && mkdir -p tcl && cd tcl &&\nif [ \"${TCL_SRCROOT}\"/macosx/configure -nt config.status ]; then\n    \"${TCL_SRCROOT}\"/macosx/configure --cache-file=../config.cache --prefix=${PREFIX} --bindir=${BINDIR} --libdir=${LIBDIR} --mandir=${MANDIR} --includedir=${INCLUDEDIR} --disable-shared ${CONFIGURE_ARGS}\nelse\n    ./config.status\nfi\n";
+			shellScript = "## tcl configure shell script phase\n\ncd \"${TCL_SRCROOT}\"/macosx &&\nif [ configure.ac -nt configure -o ../unix/configure.in -nt configure -o ../unix/tcl.m4 -nt configure -o ../unix/aclocal.m4 -nt configure ]; then\n    echo \"Running autoconf & autoheader in tcl/macosx\"\n    rm -rf autom4te.cache\n    ${AUTOCONF:-/usr/bin/autoconf} && ${AUTOHEADER:-/usr/bin/autoheader}\n    rm -rf autom4te.cache\nfi\n\ncd \"${DERIVED_FILE_DIR}\" && mkdir -p tcl && cd tcl &&\nif [ \"${TCL_SRCROOT}\"/macosx/configure -nt config.status ]; then\n    echo \"Configuring tcl\"\n    \"${TCL_SRCROOT}\"/macosx/configure --cache-file=../config.cache --prefix=${PREFIX} --bindir=${BINDIR} --libdir=${LIBDIR} --mandir=${MANDIR} --includedir=${INCLUDEDIR} --disable-shared ${CONFIGURE_ARGS}\nelse\n    ./config.status\nfi\n";
 		};
 /* End PBXShellScriptBuildPhase section */
 
@@ -2084,7 +2084,6 @@
 				INCLUDEDIR = "${PREFIX}/include";
 				INSTALL_PATH = "${BINDIR}";
 				LIBDIR = "${PREFIX}/lib";
-				MACOSX_DEPLOYMENT_TARGET = 10.4;
 				MANDIR = "${PREFIX}/man";
 				OTHER_LDFLAGS = "-headerpad_max_install_names";
 				PER_ARCH_CFLAGS_ppc = "-mcpu=G3 -mtune=G4";
@@ -2100,6 +2099,9 @@
 				WARNING_CFLAGS = (
 					"-Wall",
 					"-Wno-implicit-int",
+					"-Wextra",
+					"-Wno-unused-parameter",
+					"-Wno-missing-field-initializers",
 				);
 				ZERO_LINK = NO;
 			};
@@ -2111,6 +2113,7 @@
 				CFLAGS = "-arch ppc -arch ppc64 -arch i386 -isysroot ${SDKROOT} -mmacosx-version-min=10.4";
 				CONFIGURE_ARGS = "--disable-symbols";
 				GCC_PREPROCESSOR_DEFINITIONS = NDEBUG;
+				MACOSX_DEPLOYMENT_TARGET = 10.4;
 				SDKROOT = /Developer/SDKs/MacOSX10.4u.sdk;
 			};
 			name = ReleaseUniversal;
@@ -2184,7 +2187,6 @@
 				INCLUDEDIR = "${PREFIX}/include";
 				INSTALL_PATH = "${BINDIR}";
 				LIBDIR = "${PREFIX}/lib";
-				MACOSX_DEPLOYMENT_TARGET = 10.4;
 				MANDIR = "${PREFIX}/man";
 				OTHER_LDFLAGS = "-headerpad_max_install_names";
 				PER_ARCH_CFLAGS_ppc = "-mcpu=G3 -mtune=G4";
@@ -2200,6 +2202,9 @@
 				WARNING_CFLAGS = (
 					"-Wall",
 					"-Wno-implicit-int",
+					"-Wextra",
+					"-Wno-unused-parameter",
+					"-Wno-missing-field-initializers",
 				);
 				ZERO_LINK = YES;
 			};
@@ -2231,7 +2236,6 @@
 				INCLUDEDIR = "${PREFIX}/include";
 				INSTALL_PATH = "${BINDIR}";
 				LIBDIR = "${PREFIX}/lib";
-				MACOSX_DEPLOYMENT_TARGET = 10.4;
 				MANDIR = "${PREFIX}/man";
 				OTHER_LDFLAGS = "-headerpad_max_install_names";
 				PER_ARCH_CFLAGS_ppc = "-mcpu=G3 -mtune=G4";
@@ -2247,6 +2251,9 @@
 				WARNING_CFLAGS = (
 					"-Wall",
 					"-Wno-implicit-int",
+					"-Wextra",
+					"-Wno-unused-parameter",
+					"-Wno-missing-field-initializers",
 				);
 				ZERO_LINK = NO;
 			};
@@ -2279,7 +2286,6 @@
 				INCLUDEDIR = "${PREFIX}/include";
 				INSTALL_PATH = "${BINDIR}";
 				LIBDIR = "${PREFIX}/lib";
-				MACOSX_DEPLOYMENT_TARGET = 10.4;
 				MANDIR = "${PREFIX}/man";
 				OTHER_LDFLAGS = "-headerpad_max_install_names";
 				PER_ARCH_CFLAGS_ppc = "-mcpu=G3 -mtune=G4";
@@ -2295,6 +2301,9 @@
 				WARNING_CFLAGS = (
 					"-Wall",
 					"-Wno-implicit-int",
+					"-Wextra",
+					"-Wno-unused-parameter",
+					"-Wno-missing-field-initializers",
 				);
 				ZERO_LINK = NO;
 			};
@@ -2305,6 +2314,7 @@
 			buildSettings = {
 				CONFIGURE_ARGS = "--enable-symbols";
 				GCC_PREPROCESSOR_DEFINITIONS = "__private_extern__=extern";
+				MACOSX_DEPLOYMENT_TARGET = 10.2;
 			};
 			name = Debug;
 		};
@@ -2313,6 +2323,7 @@
 			buildSettings = {
 				CONFIGURE_ARGS = "--disable-symbols";
 				GCC_PREPROCESSOR_DEFINITIONS = NDEBUG;
+				MACOSX_DEPLOYMENT_TARGET = 10.2;
 			};
 			name = Release;
 		};
@@ -2321,6 +2332,7 @@
 			buildSettings = {
 				CONFIGURE_ARGS = "--enable-symbols";
 				GCC_PREPROCESSOR_DEFINITIONS = "";
+				MACOSX_DEPLOYMENT_TARGET = 10.2;
 			};
 			name = DebugNoFixZL;
 		};
diff --git a/macosx/tclMacOSXFCmd.c b/macosx/tclMacOSXFCmd.c
index 80e9785..51fe222 100644
--- a/macosx/tclMacOSXFCmd.c
+++ b/macosx/tclMacOSXFCmd.c
@@ -10,7 +10,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclMacOSXFCmd.c,v 1.8 2006/03/21 11:06:23 das Exp $
+ * RCS: @(#) $Id: tclMacOSXFCmd.c,v 1.9 2006/07/20 06:18:37 das Exp $
  */
 
 #include "tclInt.h"
@@ -21,7 +21,7 @@
 #include <libkern/OSByteOrder.h>
 #endif
 
-/* Darwin 8 copyfile API */
+/* Darwin 8 copyfile API. */
 #ifdef HAVE_COPYFILE
 #ifdef HAVE_COPYFILE_H
 #include <copyfile.h>
@@ -30,8 +30,14 @@ int copyfile(const char *from, const char *to, void *state, uint32_t flags);
 #define COPYFILE_ACL            (1<<0)
 #define COPYFILE_XATTR          (1<<2)
 #define COPYFILE_NOFOLLOW_SRC   (1<<18)
-#endif
-#endif
+#endif /* HAVE_COPYFILE_H */
+#if defined(HAVE_WEAK_IMPORT) && MAC_OS_X_VERSION_MIN_REQUIRED < 1040
+/* Support for weakly importing copyfile. */
+#define WEAK_IMPORT_COPYFILE
+extern int copyfile(const char *from, const char *to, void *state,
+                    uint32_t flags) WEAK_IMPORT_ATTRIBUTE;
+#endif /* HAVE_WEAK_IMPORT */
+#endif /* HAVE_COPYFILE */
 
 #include <libkern/OSByteOrder.h>
 
@@ -365,14 +371,22 @@ TclMacOSXCopyFileAttributes(
     CONST Tcl_StatBuf *statBufPtr)
 				/* Stat info for source file */
 {
-#if defined(HAVE_COPYFILE)
+#ifdef WEAK_IMPORT_COPYFILE
+    if (copyfile != NULL) {
+#endif
+#ifdef HAVE_COPYFILE
     if (copyfile(src, dst, NULL, COPYFILE_XATTR |
 	    (S_ISLNK(statBufPtr->st_mode) ? COPYFILE_NOFOLLOW_SRC :
 		                            COPYFILE_ACL)) < 0) {
 	return TCL_ERROR;
     }
     return TCL_OK;
-#elif defined(HAVE_GETATTRLIST)
+#endif /* HAVE_COPYFILE */
+#ifdef WEAK_IMPORT_COPYFILE
+    } else {
+#endif
+#if !defined(HAVE_COPYFILE) || defined(WEAK_IMPORT_COPYFILE)
+#ifdef HAVE_GETATTRLIST
     struct attrlist alist;
     fileinfobuf finfo;
     off_t *rsrcForkSize = (off_t*)(&finfo.data);
@@ -430,6 +444,10 @@ TclMacOSXCopyFileAttributes(
     return TCL_OK;
 #else
     return TCL_ERROR;
+#endif /* HAVE_GETATTRLIST */
+#endif /* !defined(HAVE_COPYFILE) || defined(WEAK_IMPORT_COPYFILE) */
+#ifdef WEAK_IMPORT_COPYFILE
+    }
 #endif
 }
 
diff --git a/macosx/tclMacOSXNotify.c b/macosx/tclMacOSXNotify.c
index a99e11b..6d892ea 100644
--- a/macosx/tclMacOSXNotify.c
+++ b/macosx/tclMacOSXNotify.c
@@ -13,7 +13,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclMacOSXNotify.c,v 1.7 2006/05/27 05:22:58 das Exp $
+ * RCS: @(#) $Id: tclMacOSXNotify.c,v 1.8 2006/07/20 06:18:37 das Exp $
  */
 
 #include "tclInt.h"
@@ -163,6 +163,32 @@ static int receivePipe = -1; /* Output end of triggerPipe */
 
 #include <libkern/OSAtomic.h>
 
+#if defined(HAVE_WEAK_IMPORT) && MAC_OS_X_VERSION_MIN_REQUIRED < 1040
+/*
+ * Support for weakly importing spinlock API.
+ */
+#define WEAK_IMPORT_SPINLOCKLOCK
+extern void	OSSpinLockLock(OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
+extern void	OSSpinLockUnlock(OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
+extern void	_spin_lock(OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
+extern void	_spin_unlock(OSSpinLock *lock) WEAK_IMPORT_ATTRIBUTE;
+static void (* lockLock)(OSSpinLock *lock) = NULL;
+static void (* lockUnlock)(OSSpinLock *lock) = NULL;
+static pthread_once_t spinLockLockInitControl = PTHREAD_ONCE_INIT;
+static void SpinLockLockInit(void) {
+    lockLock   = OSSpinLockLock   != NULL ? OSSpinLockLock   : _spin_lock;
+    lockUnlock = OSSpinLockUnlock != NULL ? OSSpinLockUnlock : _spin_unlock;
+    if (lockLock == NULL || lockUnlock == NULL) {
+	Tcl_Panic("SpinLockLockInit: no spinlock API available.");
+    }
+}
+#define SpinLockLock(p) 	lockLock(p)
+#define SpinLockUnlock(p)	lockUnlock(p)
+#else
+#define SpinLockLock(p) 	OSSpinLockLock(p)
+#define SpinLockUnlock(p)	OSSpinLockUnlock(p)
+#endif /* HAVE_WEAK_IMPORT */
+
 #else
 /*
  * Otherwise, use commpage spinlock SPI directly.
@@ -171,8 +197,8 @@ static int receivePipe = -1; /* Output end of triggerPipe */
 typedef uint32_t OSSpinLock;
 extern void	_spin_lock(OSSpinLock *lock);
 extern void	_spin_unlock(OSSpinLock *lock);
-#define OSSpinLockLock(p)	_spin_lock(p)
-#define OSSpinLockUnlock(p)	_spin_unlock(p)
+#define SpinLockLock(p) 	_spin_lock(p)
+#define SpinLockUnlock(p)	_spin_unlock(p)
 
 #endif /* HAVE_LIBKERN_OSATOMIC_H && HAVE_OSSPINLOCKLOCK */
 
@@ -187,10 +213,10 @@ static OSSpinLock notifierLock = 0;
  * Macros abstracting notifier locking/unlocking
  */
 
-#define LOCK_NOTIFIER_INIT	OSSpinLockLock(&notifierInitLock)
-#define UNLOCK_NOTIFIER_INIT	OSSpinLockUnlock(&notifierInitLock)
-#define LOCK_NOTIFIER		OSSpinLockLock(&notifierLock)
-#define UNLOCK_NOTIFIER		OSSpinLockUnlock(&notifierLock)
+#define LOCK_NOTIFIER_INIT	SpinLockLock(&notifierInitLock)
+#define UNLOCK_NOTIFIER_INIT	SpinLockUnlock(&notifierInitLock)
+#define LOCK_NOTIFIER		SpinLockLock(&notifierLock)
+#define UNLOCK_NOTIFIER		SpinLockUnlock(&notifierLock)
 
 /*
  * The pollState bits
@@ -222,7 +248,13 @@ static int	atForkInit = 0;
 static void	AtForkPrepare(void);
 static void	AtForkParent(void);
 static void	AtForkChild(void);
-#endif
+#if defined(HAVE_WEAK_IMPORT) && MAC_OS_X_VERSION_MIN_REQUIRED < 1040
+/* Support for weakly importing pthread_atfork. */
+#define WEAK_IMPORT_PTHREAD_ATFORK
+extern int pthread_atfork(void (*prepare)(void), void (*parent)(void),
+                          void (*child)(void)) WEAK_IMPORT_ATTRIBUTE;
+#endif /* HAVE_WEAK_IMPORT */
+#endif /* HAVE_PTHREAD_ATFORK */
 
 /*
  *----------------------------------------------------------------------
@@ -247,8 +279,17 @@ Tcl_InitNotifier(void)
 
     tsdPtr->eventReady = 0;
 
+#ifdef WEAK_IMPORT_SPINLOCKLOCK
+    /*
+     * Initialize support for weakly imported spinlock API.
+     */
+    if (pthread_once(&spinLockLockInitControl, SpinLockLockInit)) {
+	Tcl_Panic("Tcl_InitNotifier: pthread_once failed.");
+    }
+#endif
+
     /*
-     * Initialize CFRunLoopSource and add it to CFRunLoop of this thread
+     * Initialize CFRunLoopSource and add it to CFRunLoop of this thread.
      */
 
     if (!tsdPtr->runLoop) {
@@ -267,28 +308,31 @@ Tcl_InitNotifier(void)
 	tsdPtr->runLoop = runLoop;
     }
 
-    /*
-     * Initialize trigger pipe and start the Notifier thread if necessary.
-     */
-
     LOCK_NOTIFIER_INIT;
 #ifdef HAVE_PTHREAD_ATFORK
     /*
-     * Install pthread_atfork handlers to reinstall the notifier thread in the
+     * Install pthread_atfork handlers to reinitialize the notifier in the
      * child of a fork.
      */
 
-    if (!atForkInit) {
+    if (
+#ifdef WEAK_IMPORT_PTHREAD_ATFORK
+	    pthread_atfork != NULL &&
+#endif
+	    !atForkInit) {
 	int result = pthread_atfork(AtForkPrepare, AtForkParent, AtForkChild);
 	if (result) { 
-	    Tcl_Panic("Tcl_InitNotifier: pthread_atfork failed");
+	    Tcl_Panic("Tcl_InitNotifier: pthread_atfork failed.");
 	}
 	atForkInit = 1;
     }
 #endif
     if (notifierCount == 0) {
-	int fds[2], status, result;
-	pthread_attr_t attr;
+	int fds[2], status;
+
+	/*
+	 * Initialize trigger pipe.
+	 */
 
 	if (pipe(fds) != 0) {
 	    Tcl_Panic("Tcl_InitNotifier: could not create trigger pipe.");
@@ -308,16 +352,13 @@ Tcl_InitNotifier(void)
 	receivePipe = fds[0];
 	triggerPipe = fds[1];
 
-	pthread_attr_init(&attr);
-	pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);
-	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
-	pthread_attr_setstacksize(&attr, 60 * 1024);
-	result = pthread_create(&notifierThread, &attr,
-		(void * (*)(void *))NotifierThreadProc, NULL);
-	pthread_attr_destroy(&attr);
-	if (result) {
-	    Tcl_Panic("Tcl_InitNotifier: unable to start notifier thread.");
-	}
+	/*
+	 * Create notifier thread lazily in Tcl_WaitForEvent() to avoid
+	 * interfering with fork() followed immediately by execve()
+	 * (cannot execve() when more than one thread is present).
+	 */
+	
+	notifierThread = 0;
     }
     notifierCount++;
     UNLOCK_NOTIFIER_INIT;
@@ -378,9 +419,12 @@ Tcl_FinalizeNotifier(
 	write(triggerPipe, "q", 1);
 	close(triggerPipe);
 
-	result = pthread_join(notifierThread, NULL);
-	if (result) {
-	    Tcl_Panic("Tcl_FinalizeNotifier: unable to join notifier thread.");
+	if (notifierThread) {
+	    result = pthread_join(notifierThread, NULL);
+	    if (result) {
+		Tcl_Panic("Tcl_FinalizeNotifier: unable to join notifier thread.");
+	    }
+	    notifierThread = 0;
 	}
 
 	close(receivePipe);
@@ -784,6 +828,28 @@ Tcl_WaitForEvent(
     }
 
     /*
+     * Start notifier thread if necessary.
+     */
+
+    LOCK_NOTIFIER_INIT;
+    if (!notifierThread) {
+	int result;
+	pthread_attr_t attr;
+
+	pthread_attr_init(&attr);
+	pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
+	pthread_attr_setstacksize(&attr, 60 * 1024);
+	result = pthread_create(&notifierThread, &attr,
+		(void * (*)(void *))NotifierThreadProc, NULL);
+	pthread_attr_destroy(&attr);
+	if (result || !notifierThread) {
+	    Tcl_Panic("Tcl_WaitForEvent: unable to start notifier thread.");
+	}
+    }
+    UNLOCK_NOTIFIER_INIT;
+
+    /*
      * Place this thread on the list of interested threads, signal the
      * notifier thread, and wait for a response or a timeout.
      */
@@ -1158,9 +1224,13 @@ AtForkChild(void)
     }
     if (notifierCount > 0) {
 	notifierCount = 0;
-	/* Note that Tcl_FinalizeNotifier does not use its clientData
-	 * parameter, so discard return value of Tcl_InitNotifier here and
-	 * leave stale clientData in tclNotify.c's ThreadSpecificData.
+	/*
+	 * Assume that the return value of Tcl_InitNotifier() in the child
+	 * will be identical to the one stored as clientData in tclNotify.c's
+	 * ThreadSpecificData by the parent's TclInitNotifier(), so discard
+	 * the return value here. This assumption may require the fork() to
+	 * be executed in the main thread of the parent, otherwise
+	 * Tcl_AlertNotifier() may break in the child.
 	 */
 	Tcl_InitNotifier();
     }
diff --git a/unix/configure b/unix/configure
index 3731800..05db728 100755
--- a/unix/configure
+++ b/unix/configure
@@ -852,13 +852,13 @@ Optional Features:
   --enable-shared         build and link with shared libraries (default: on)
   --enable-64bit          enable 64bit support (default: off)
   --enable-64bit-vis      enable 64bit Sparc VIS support (default: off)
-  --enable-corefoundation use CoreFoundation API on MacOSX (default: yes)
-  --disable-load          disallow dynamic loading and "load" command
-                          (default: enabled)
+  --enable-corefoundation use CoreFoundation API on MacOSX (default: on)
+  --enable-load           allow dynamic loading and "load" command (default:
+                          on)
   --enable-symbols        build with debugging symbols (default: off)
   --enable-langinfo       use nl_langinfo if possible to determine encoding at
                           startup, otherwise use old heuristic (default: on)
-  --enable-dll-unloading  turn on the 'unload' command (default: on)
+  --enable-dll-unloading  enable the 'unload' command (default: on)
   --enable-framework      package shared libraries in MacOSX frameworks
                           (default: off)
 
@@ -2364,6 +2364,7 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 # Do this early, otherwise an autoconf bug throws errors on configure
 #--------------------------------------------------------------------
 
+
 ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'
 ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -2859,7 +2860,7 @@ if test "${tcl_cv_dirent_h+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
 
-cat >conftest.$ac_ext <<_ACEOF
+    cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
@@ -4924,7 +4925,8 @@ echo $ECHO_N "checking for pthread_attr_get_np declaration... $ECHO_C" >&6
 if test "${tcl_cv_grep_pthread_attr_get_np+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
-  cat >conftest.$ac_ext <<_ACEOF
+
+		cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
@@ -5059,7 +5061,8 @@ echo $ECHO_N "checking for pthread_getattr_np declaration... $ECHO_C" >&6
 if test "${tcl_cv_grep_pthread_getattr_np+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
-  cat >conftest.$ac_ext <<_ACEOF
+
+		    cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
@@ -7417,736 +7420,20 @@ cat >>confdefs.h <<\_ACEOF
 #define HAVE_COREFOUNDATION 1
 _ACEOF
 
-
-for ac_header in libkern/OSAtomic.h
-do
-as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
-if eval "test \"\${$as_ac_Header+set}\" = set"; then
-  echo "$as_me:$LINENO: checking for $ac_header" >&5
-echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
-if eval "test \"\${$as_ac_Header+set}\" = set"; then
-  echo $ECHO_N "(cached) $ECHO_C" >&6
-fi
-echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
-echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
-else
-  # Is the header compilable?
-echo "$as_me:$LINENO: checking $ac_header usability" >&5
-echo $ECHO_N "checking $ac_header usability... $ECHO_C" >&6
-cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-$ac_includes_default
-#include <$ac_header>
-_ACEOF
-rm -f conftest.$ac_objext
-if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
-  (eval $ac_compile) 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"
-			 || test ! -s conftest.err'
-  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; } &&
-	 { ac_try='test -s conftest.$ac_objext'
-  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; }; then
-  ac_header_compiler=yes
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-ac_header_compiler=no
-fi
-rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
-echo "$as_me:$LINENO: result: $ac_header_compiler" >&5
-echo "${ECHO_T}$ac_header_compiler" >&6
-
-# Is the header present?
-echo "$as_me:$LINENO: checking $ac_header presence" >&5
-echo $ECHO_N "checking $ac_header presence... $ECHO_C" >&6
-cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-#include <$ac_header>
-_ACEOF
-if { (eval echo "$as_me:$LINENO: \"$ac_cpp conftest.$ac_ext\"") >&5
-  (eval $ac_cpp conftest.$ac_ext) 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } >/dev/null; then
-  if test -s conftest.err; then
-    ac_cpp_err=$ac_c_preproc_warn_flag
-    ac_cpp_err=$ac_cpp_err$ac_c_werror_flag
-  else
-    ac_cpp_err=
-  fi
-else
-  ac_cpp_err=yes
-fi
-if test -z "$ac_cpp_err"; then
-  ac_header_preproc=yes
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-  ac_header_preproc=no
-fi
-rm -f conftest.err conftest.$ac_ext
-echo "$as_me:$LINENO: result: $ac_header_preproc" >&5
-echo "${ECHO_T}$ac_header_preproc" >&6
-
-# So?  What about this header?
-case $ac_header_compiler:$ac_header_preproc:$ac_c_preproc_warn_flag in
-  yes:no: )
-    { echo "$as_me:$LINENO: WARNING: $ac_header: accepted by the compiler, rejected by the preprocessor!" >&5
-echo "$as_me: WARNING: $ac_header: accepted by the compiler, rejected by the preprocessor!" >&2;}
-    { echo "$as_me:$LINENO: WARNING: $ac_header: proceeding with the compiler's result" >&5
-echo "$as_me: WARNING: $ac_header: proceeding with the compiler's result" >&2;}
-    ac_header_preproc=yes
-    ;;
-  no:yes:* )
-    { echo "$as_me:$LINENO: WARNING: $ac_header: present but cannot be compiled" >&5
-echo "$as_me: WARNING: $ac_header: present but cannot be compiled" >&2;}
-    { echo "$as_me:$LINENO: WARNING: $ac_header:     check for missing prerequisite headers?" >&5
-echo "$as_me: WARNING: $ac_header:     check for missing prerequisite headers?" >&2;}
-    { echo "$as_me:$LINENO: WARNING: $ac_header: see the Autoconf documentation" >&5
-echo "$as_me: WARNING: $ac_header: see the Autoconf documentation" >&2;}
-    { echo "$as_me:$LINENO: WARNING: $ac_header:     section \"Present But Cannot Be Compiled\"" >&5
-echo "$as_me: WARNING: $ac_header:     section \"Present But Cannot Be Compiled\"" >&2;}
-    { echo "$as_me:$LINENO: WARNING: $ac_header: proceeding with the preprocessor's result" >&5
-echo "$as_me: WARNING: $ac_header: proceeding with the preprocessor's result" >&2;}
-    { echo "$as_me:$LINENO: WARNING: $ac_header: in the future, the compiler will take precedence" >&5
-echo "$as_me: WARNING: $ac_header: in the future, the compiler will take precedence" >&2;}
-    (
-      cat <<\_ASBOX
-## ------------------------------ ##
-## Report this to the tcl lists.  ##
-## ------------------------------ ##
-_ASBOX
-    ) |
-      sed "s/^/$as_me: WARNING:     /" >&2
-    ;;
-esac
-echo "$as_me:$LINENO: checking for $ac_header" >&5
-echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
-if eval "test \"\${$as_ac_Header+set}\" = set"; then
-  echo $ECHO_N "(cached) $ECHO_C" >&6
-else
-  eval "$as_ac_Header=\$ac_header_preproc"
-fi
-echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
-echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
-
-fi
-if test `eval echo '${'$as_ac_Header'}'` = yes; then
-  cat >>confdefs.h <<_ACEOF
-#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-
-done
-
-
-for ac_func in OSSpinLockLock
-do
-as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
-echo "$as_me:$LINENO: checking for $ac_func" >&5
-echo $ECHO_N "checking for $ac_func... $ECHO_C" >&6
-if eval "test \"\${$as_ac_var+set}\" = set"; then
-  echo $ECHO_N "(cached) $ECHO_C" >&6
-else
-  cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-/* Define $ac_func to an innocuous variant, in case <limits.h> declares $ac_func.
-   For example, HP-UX 11i <limits.h> declares gettimeofday.  */
-#define $ac_func innocuous_$ac_func
-
-/* System header to define __stub macros and hopefully few prototypes,
-    which can conflict with char $ac_func (); below.
-    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
-    <limits.h> exists even on freestanding compilers.  */
-
-#ifdef __STDC__
-# include <limits.h>
-#else
-# include <assert.h>
-#endif
-
-#undef $ac_func
-
-/* Override any gcc2 internal prototype to avoid an error.  */
-#ifdef __cplusplus
-extern "C"
-{
-#endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
-char $ac_func ();
-/* The GNU C library defines this for functions which it implements
-    to always fail with ENOSYS.  Some functions are actually named
-    something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
-choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
-#endif
-
-int
-main ()
-{
-return f != $ac_func;
-  ;
-  return 0;
-}
-_ACEOF
-rm -f conftest.$ac_objext conftest$ac_exeext
-if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
-  (eval $ac_link) 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"
-			 || test ! -s conftest.err'
-  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; } &&
-	 { ac_try='test -s conftest$ac_exeext'
-  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; }; then
-  eval "$as_ac_var=yes"
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-eval "$as_ac_var=no"
-fi
-rm -f conftest.err conftest.$ac_objext \
-      conftest$ac_exeext conftest.$ac_ext
-fi
-echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_var'}'`" >&5
-echo "${ECHO_T}`eval echo '${'$as_ac_var'}'`" >&6
-if test `eval echo '${'$as_ac_var'}'` = yes; then
-  cat >>confdefs.h <<_ACEOF
-#define `echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-done
-
-
-for ac_func in pthread_atfork
-do
-as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
-echo "$as_me:$LINENO: checking for $ac_func" >&5
-echo $ECHO_N "checking for $ac_func... $ECHO_C" >&6
-if eval "test \"\${$as_ac_var+set}\" = set"; then
-  echo $ECHO_N "(cached) $ECHO_C" >&6
-else
-  cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-/* Define $ac_func to an innocuous variant, in case <limits.h> declares $ac_func.
-   For example, HP-UX 11i <limits.h> declares gettimeofday.  */
-#define $ac_func innocuous_$ac_func
-
-/* System header to define __stub macros and hopefully few prototypes,
-    which can conflict with char $ac_func (); below.
-    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
-    <limits.h> exists even on freestanding compilers.  */
-
-#ifdef __STDC__
-# include <limits.h>
-#else
-# include <assert.h>
-#endif
-
-#undef $ac_func
-
-/* Override any gcc2 internal prototype to avoid an error.  */
-#ifdef __cplusplus
-extern "C"
-{
-#endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
-char $ac_func ();
-/* The GNU C library defines this for functions which it implements
-    to always fail with ENOSYS.  Some functions are actually named
-    something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
-choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
-#endif
-
-int
-main ()
-{
-return f != $ac_func;
-  ;
-  return 0;
-}
-_ACEOF
-rm -f conftest.$ac_objext conftest$ac_exeext
-if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
-  (eval $ac_link) 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"
-			 || test ! -s conftest.err'
-  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; } &&
-	 { ac_try='test -s conftest$ac_exeext'
-  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; }; then
-  eval "$as_ac_var=yes"
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-eval "$as_ac_var=no"
-fi
-rm -f conftest.err conftest.$ac_objext \
-      conftest$ac_exeext conftest.$ac_ext
-fi
-echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_var'}'`" >&5
-echo "${ECHO_T}`eval echo '${'$as_ac_var'}'`" >&6
-if test `eval echo '${'$as_ac_var'}'` = yes; then
-  cat >>confdefs.h <<_ACEOF
-#define `echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-done
-
+		else
+		    tcl_corefoundation=no
 		fi
 	    fi
 
-for ac_header in copyfile.h
-do
-as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
-if eval "test \"\${$as_ac_Header+set}\" = set"; then
-  echo "$as_me:$LINENO: checking for $ac_header" >&5
-echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
-if eval "test \"\${$as_ac_Header+set}\" = set"; then
-  echo $ECHO_N "(cached) $ECHO_C" >&6
-fi
-echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
-echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
-else
-  # Is the header compilable?
-echo "$as_me:$LINENO: checking $ac_header usability" >&5
-echo $ECHO_N "checking $ac_header usability... $ECHO_C" >&6
-cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-$ac_includes_default
-#include <$ac_header>
-_ACEOF
-rm -f conftest.$ac_objext
-if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
-  (eval $ac_compile) 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"
-			 || test ! -s conftest.err'
-  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; } &&
-	 { ac_try='test -s conftest.$ac_objext'
-  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; }; then
-  ac_header_compiler=yes
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-ac_header_compiler=no
-fi
-rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
-echo "$as_me:$LINENO: result: $ac_header_compiler" >&5
-echo "${ECHO_T}$ac_header_compiler" >&6
-
-# Is the header present?
-echo "$as_me:$LINENO: checking $ac_header presence" >&5
-echo $ECHO_N "checking $ac_header presence... $ECHO_C" >&6
-cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-#include <$ac_header>
-_ACEOF
-if { (eval echo "$as_me:$LINENO: \"$ac_cpp conftest.$ac_ext\"") >&5
-  (eval $ac_cpp conftest.$ac_ext) 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } >/dev/null; then
-  if test -s conftest.err; then
-    ac_cpp_err=$ac_c_preproc_warn_flag
-    ac_cpp_err=$ac_cpp_err$ac_c_werror_flag
-  else
-    ac_cpp_err=
-  fi
-else
-  ac_cpp_err=yes
-fi
-if test -z "$ac_cpp_err"; then
-  ac_header_preproc=yes
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-  ac_header_preproc=no
-fi
-rm -f conftest.err conftest.$ac_ext
-echo "$as_me:$LINENO: result: $ac_header_preproc" >&5
-echo "${ECHO_T}$ac_header_preproc" >&6
-
-# So?  What about this header?
-case $ac_header_compiler:$ac_header_preproc:$ac_c_preproc_warn_flag in
-  yes:no: )
-    { echo "$as_me:$LINENO: WARNING: $ac_header: accepted by the compiler, rejected by the preprocessor!" >&5
-echo "$as_me: WARNING: $ac_header: accepted by the compiler, rejected by the preprocessor!" >&2;}
-    { echo "$as_me:$LINENO: WARNING: $ac_header: proceeding with the compiler's result" >&5
-echo "$as_me: WARNING: $ac_header: proceeding with the compiler's result" >&2;}
-    ac_header_preproc=yes
-    ;;
-  no:yes:* )
-    { echo "$as_me:$LINENO: WARNING: $ac_header: present but cannot be compiled" >&5
-echo "$as_me: WARNING: $ac_header: present but cannot be compiled" >&2;}
-    { echo "$as_me:$LINENO: WARNING: $ac_header:     check for missing prerequisite headers?" >&5
-echo "$as_me: WARNING: $ac_header:     check for missing prerequisite headers?" >&2;}
-    { echo "$as_me:$LINENO: WARNING: $ac_header: see the Autoconf documentation" >&5
-echo "$as_me: WARNING: $ac_header: see the Autoconf documentation" >&2;}
-    { echo "$as_me:$LINENO: WARNING: $ac_header:     section \"Present But Cannot Be Compiled\"" >&5
-echo "$as_me: WARNING: $ac_header:     section \"Present But Cannot Be Compiled\"" >&2;}
-    { echo "$as_me:$LINENO: WARNING: $ac_header: proceeding with the preprocessor's result" >&5
-echo "$as_me: WARNING: $ac_header: proceeding with the preprocessor's result" >&2;}
-    { echo "$as_me:$LINENO: WARNING: $ac_header: in the future, the compiler will take precedence" >&5
-echo "$as_me: WARNING: $ac_header: in the future, the compiler will take precedence" >&2;}
-    (
-      cat <<\_ASBOX
-## ------------------------------ ##
-## Report this to the tcl lists.  ##
-## ------------------------------ ##
-_ASBOX
-    ) |
-      sed "s/^/$as_me: WARNING:     /" >&2
-    ;;
-esac
-echo "$as_me:$LINENO: checking for $ac_header" >&5
-echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
-if eval "test \"\${$as_ac_Header+set}\" = set"; then
-  echo $ECHO_N "(cached) $ECHO_C" >&6
-else
-  eval "$as_ac_Header=\$ac_header_preproc"
-fi
-echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
-echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
-
-fi
-if test `eval echo '${'$as_ac_Header'}'` = yes; then
-  cat >>confdefs.h <<_ACEOF
-#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-
-done
-
-
-for ac_func in copyfile
-do
-as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
-echo "$as_me:$LINENO: checking for $ac_func" >&5
-echo $ECHO_N "checking for $ac_func... $ECHO_C" >&6
-if eval "test \"\${$as_ac_var+set}\" = set"; then
-  echo $ECHO_N "(cached) $ECHO_C" >&6
-else
-  cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-/* Define $ac_func to an innocuous variant, in case <limits.h> declares $ac_func.
-   For example, HP-UX 11i <limits.h> declares gettimeofday.  */
-#define $ac_func innocuous_$ac_func
-
-/* System header to define __stub macros and hopefully few prototypes,
-    which can conflict with char $ac_func (); below.
-    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
-    <limits.h> exists even on freestanding compilers.  */
-
-#ifdef __STDC__
-# include <limits.h>
-#else
-# include <assert.h>
-#endif
-
-#undef $ac_func
-
-/* Override any gcc2 internal prototype to avoid an error.  */
-#ifdef __cplusplus
-extern "C"
-{
-#endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
-char $ac_func ();
-/* The GNU C library defines this for functions which it implements
-    to always fail with ENOSYS.  Some functions are actually named
-    something starting with __ and the normal name is an alias.  */
-#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
-choke me
-#else
-char (*f) () = $ac_func;
-#endif
-#ifdef __cplusplus
-}
-#endif
-
-int
-main ()
-{
-return f != $ac_func;
-  ;
-  return 0;
-}
-_ACEOF
-rm -f conftest.$ac_objext conftest$ac_exeext
-if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
-  (eval $ac_link) 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"
-			 || test ! -s conftest.err'
-  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; } &&
-	 { ac_try='test -s conftest$ac_exeext'
-  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; }; then
-  eval "$as_ac_var=yes"
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-eval "$as_ac_var=no"
-fi
-rm -f conftest.err conftest.$ac_objext \
-      conftest$ac_exeext conftest.$ac_ext
-fi
-echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_var'}'`" >&5
-echo "${ECHO_T}`eval echo '${'$as_ac_var'}'`" >&6
-if test `eval echo '${'$as_ac_var'}'` = yes; then
-  cat >>confdefs.h <<_ACEOF
-#define `echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-done
-
-
 cat >>confdefs.h <<\_ACEOF
 #define MAC_OSX_TCL 1
 _ACEOF
 
 
 cat >>confdefs.h <<\_ACEOF
-#define USE_VFORK 1
-_ACEOF
-
-
-cat >>confdefs.h <<\_ACEOF
-#define TCL_DEFAULT_ENCODING "utf-8"
-_ACEOF
-
-
-cat >>confdefs.h <<\_ACEOF
 #define MODULE_SCOPE __private_extern__
 _ACEOF
 
-
-cat >>confdefs.h <<\_ACEOF
-#define TCL_LOAD_FROM_MEMORY 1
-_ACEOF
-
-	    # prior to Darwin 7, realpath is not threadsafe, so don't
-	    # use it when threads are enabled, c.f. bug # 711232:
-	    echo "$as_me:$LINENO: checking for realpath" >&5
-echo $ECHO_N "checking for realpath... $ECHO_C" >&6
-if test "${ac_cv_func_realpath+set}" = set; then
-  echo $ECHO_N "(cached) $ECHO_C" >&6
-else
-  cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-/* Define realpath to an innocuous variant, in case <limits.h> declares realpath.
-   For example, HP-UX 11i <limits.h> declares gettimeofday.  */
-#define realpath innocuous_realpath
-
-/* System header to define __stub macros and hopefully few prototypes,
-    which can conflict with char realpath (); below.
-    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
-    <limits.h> exists even on freestanding compilers.  */
-
-#ifdef __STDC__
-# include <limits.h>
-#else
-# include <assert.h>
-#endif
-
-#undef realpath
-
-/* Override any gcc2 internal prototype to avoid an error.  */
-#ifdef __cplusplus
-extern "C"
-{
-#endif
-/* We use char because int might match the return type of a gcc2
-   builtin and then its argument prototype would still apply.  */
-char realpath ();
-/* The GNU C library defines this for functions which it implements
-    to always fail with ENOSYS.  Some functions are actually named
-    something starting with __ and the normal name is an alias.  */
-#if defined (__stub_realpath) || defined (__stub___realpath)
-choke me
-#else
-char (*f) () = realpath;
-#endif
-#ifdef __cplusplus
-}
-#endif
-
-int
-main ()
-{
-return f != realpath;
-  ;
-  return 0;
-}
-_ACEOF
-rm -f conftest.$ac_objext conftest$ac_exeext
-if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
-  (eval $ac_link) 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"
-			 || test ! -s conftest.err'
-  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; } &&
-	 { ac_try='test -s conftest$ac_exeext'
-  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; }; then
-  ac_cv_func_realpath=yes
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-ac_cv_func_realpath=no
-fi
-rm -f conftest.err conftest.$ac_objext \
-      conftest$ac_exeext conftest.$ac_ext
-fi
-echo "$as_me:$LINENO: result: $ac_cv_func_realpath" >&5
-echo "${ECHO_T}$ac_cv_func_realpath" >&6
-
-	    if test $ac_cv_func_realpath = yes -a "${TCL_THREADS}" = 1 \
-		    -a `uname -r | awk -F. '{print $1}'` -lt 7 ; then
-		ac_cv_func_realpath=no
-	    fi
 	    ;;
 	NEXTSTEP-*)
 	    SHLIB_CFLAGS=""
@@ -10329,6 +9616,13 @@ _ACEOF
 
 fi
 
+
+if test "`uname -s`" = "Darwin" && test "${TCL_THREADS}" = 1 && \
+	test "`uname -r | awk -F. '{print $1}'`" -lt 7; then
+    # prior to Darwin 7, realpath is not threadsafe, so don't
+    # use it when threads are enabled, c.f. bug # 711232
+    ac_cv_func_realpath=no
+fi
 echo "$as_me:$LINENO: checking for realpath" >&5
 echo $ECHO_N "checking for realpath... $ECHO_C" >&6
 if test "${ac_cv_func_realpath+set}" = set; then
@@ -10908,7 +10202,8 @@ echo $ECHO_N "checking for fd_set in sys/types... $ECHO_C" >&6
 if test "${tcl_cv_type_fd_set+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
-  cat >conftest.$ac_ext <<_ACEOF
+
+    cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
@@ -10963,7 +10258,8 @@ echo $ECHO_N "checking for fd_mask in sys/select... $ECHO_C" >&6
 if test "${tcl_cv_grep_fd_mask+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
-  cat >conftest.$ac_ext <<_ACEOF
+
+	cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
@@ -11584,7 +10880,8 @@ echo $ECHO_N "checking tm_tzadj in struct tm... $ECHO_C" >&6
 if test "${tcl_cv_member_tm_tzadj+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
-  cat >conftest.$ac_ext <<_ACEOF
+
+	cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
@@ -11645,7 +10942,8 @@ echo $ECHO_N "checking tm_gmtoff in struct tm... $ECHO_C" >&6
 if test "${tcl_cv_member_tm_gmtoff+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
-  cat >conftest.$ac_ext <<_ACEOF
+
+	cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
@@ -11710,7 +11008,8 @@ echo $ECHO_N "checking long timezone variable... $ECHO_C" >&6
 if test "${tcl_cv_timezone_long+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
-  cat >conftest.$ac_ext <<_ACEOF
+
+	cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
@@ -11775,7 +11074,8 @@ echo $ECHO_N "checking time_t timezone variable... $ECHO_C" >&6
 if test "${tcl_cv_timezone_time+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
-  cat >conftest.$ac_ext <<_ACEOF
+
+	    cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
@@ -13187,7 +12487,8 @@ echo $ECHO_N "checking for socklen_t... $ECHO_C" >&6
 if test "${ac_cv_type_socklen_t+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
-  cat >conftest.$ac_ext <<_ACEOF
+
+    cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
@@ -13342,7 +12643,8 @@ echo $ECHO_N "checking union wait... $ECHO_C" >&6
 if test "${tcl_cv_union_wait+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
-  cat >conftest.$ac_ext <<_ACEOF
+
+    cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
@@ -13879,7 +13181,8 @@ echo $ECHO_N "checking for gettimeofday declaration... $ECHO_C" >&6
 if test "${tcl_cv_grep_gettimeofday+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
-  cat >conftest.$ac_ext <<_ACEOF
+
+    cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
@@ -13981,7 +13284,8 @@ echo $ECHO_N "checking signed char declarations... $ECHO_C" >&6
 if test "${tcl_cv_char_signed+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
-  cat >conftest.$ac_ext <<_ACEOF
+
+    cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF
 cat confdefs.h >>conftest.$ac_ext
@@ -14049,7 +13353,8 @@ echo $ECHO_N "checking for a putenv() that copies the buffer... $ECHO_C" >&6
 if test "${tcl_cv_putenv_copy+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
-  if test "$cross_compiling" = yes; then
+
+    if test "$cross_compiling" = yes; then
   tcl_cv_putenv_copy=no
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -14061,7 +13366,7 @@ cat >>conftest.$ac_ext <<_ACEOF
 
 	#include <stdlib.h>
 	#define OURVAR "havecopy=yes"
-	int main (int argc, char *argv)
+	int main (int argc, char *argv[])
 	{
 	    char *foo, *bar;
 	    foo = (char *)strdup(OURVAR);
@@ -14100,7 +13405,6 @@ tcl_cv_putenv_copy=yes
 fi
 rm -f core *.core gmon.out bb.out conftest$ac_exeext conftest.$ac_objext conftest.$ac_ext
 fi
-
 fi
 echo "$as_me:$LINENO: result: $tcl_cv_putenv_copy" >&5
 echo "${ECHO_T}$tcl_cv_putenv_copy" >&6
@@ -14448,9 +13752,10 @@ done
 
 
 #--------------------------------------------------------------------
-# Check for support of getattrlist function (Darwin, HFS+)
+# Darwin specific API checks and defines
 #--------------------------------------------------------------------
 
+if test "`uname -s`" = "Darwin" ; then
 
 for ac_func in getattrlist
 do
@@ -14554,6 +13859,855 @@ fi
 done
 
 
+for ac_header in copyfile.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
+  echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+fi
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+else
+  # Is the header compilable?
+echo "$as_me:$LINENO: checking $ac_header usability" >&5
+echo $ECHO_N "checking $ac_header usability... $ECHO_C" >&6
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+$ac_includes_default
+#include <$ac_header>
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_header_compiler=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_header_compiler=no
+fi
+rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+echo "$as_me:$LINENO: result: $ac_header_compiler" >&5
+echo "${ECHO_T}$ac_header_compiler" >&6
+
+# Is the header present?
+echo "$as_me:$LINENO: checking $ac_header presence" >&5
+echo $ECHO_N "checking $ac_header presence... $ECHO_C" >&6
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <$ac_header>
+_ACEOF
+if { (eval echo "$as_me:$LINENO: \"$ac_cpp conftest.$ac_ext\"") >&5
+  (eval $ac_cpp conftest.$ac_ext) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } >/dev/null; then
+  if test -s conftest.err; then
+    ac_cpp_err=$ac_c_preproc_warn_flag
+    ac_cpp_err=$ac_cpp_err$ac_c_werror_flag
+  else
+    ac_cpp_err=
+  fi
+else
+  ac_cpp_err=yes
+fi
+if test -z "$ac_cpp_err"; then
+  ac_header_preproc=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+  ac_header_preproc=no
+fi
+rm -f conftest.err conftest.$ac_ext
+echo "$as_me:$LINENO: result: $ac_header_preproc" >&5
+echo "${ECHO_T}$ac_header_preproc" >&6
+
+# So?  What about this header?
+case $ac_header_compiler:$ac_header_preproc:$ac_c_preproc_warn_flag in
+  yes:no: )
+    { echo "$as_me:$LINENO: WARNING: $ac_header: accepted by the compiler, rejected by the preprocessor!" >&5
+echo "$as_me: WARNING: $ac_header: accepted by the compiler, rejected by the preprocessor!" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header: proceeding with the compiler's result" >&5
+echo "$as_me: WARNING: $ac_header: proceeding with the compiler's result" >&2;}
+    ac_header_preproc=yes
+    ;;
+  no:yes:* )
+    { echo "$as_me:$LINENO: WARNING: $ac_header: present but cannot be compiled" >&5
+echo "$as_me: WARNING: $ac_header: present but cannot be compiled" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header:     check for missing prerequisite headers?" >&5
+echo "$as_me: WARNING: $ac_header:     check for missing prerequisite headers?" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header: see the Autoconf documentation" >&5
+echo "$as_me: WARNING: $ac_header: see the Autoconf documentation" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header:     section \"Present But Cannot Be Compiled\"" >&5
+echo "$as_me: WARNING: $ac_header:     section \"Present But Cannot Be Compiled\"" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header: proceeding with the preprocessor's result" >&5
+echo "$as_me: WARNING: $ac_header: proceeding with the preprocessor's result" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header: in the future, the compiler will take precedence" >&5
+echo "$as_me: WARNING: $ac_header: in the future, the compiler will take precedence" >&2;}
+    (
+      cat <<\_ASBOX
+## ------------------------------ ##
+## Report this to the tcl lists.  ##
+## ------------------------------ ##
+_ASBOX
+    ) |
+      sed "s/^/$as_me: WARNING:     /" >&2
+    ;;
+esac
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  eval "$as_ac_Header=\$ac_header_preproc"
+fi
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+
+fi
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+
+done
+
+
+for ac_func in copyfile
+do
+as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_func" >&5
+echo $ECHO_N "checking for $ac_func... $ECHO_C" >&6
+if eval "test \"\${$as_ac_var+set}\" = set"; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+/* Define $ac_func to an innocuous variant, in case <limits.h> declares $ac_func.
+   For example, HP-UX 11i <limits.h> declares gettimeofday.  */
+#define $ac_func innocuous_$ac_func
+
+/* System header to define __stub macros and hopefully few prototypes,
+    which can conflict with char $ac_func (); below.
+    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
+    <limits.h> exists even on freestanding compilers.  */
+
+#ifdef __STDC__
+# include <limits.h>
+#else
+# include <assert.h>
+#endif
+
+#undef $ac_func
+
+/* Override any gcc2 internal prototype to avoid an error.  */
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+/* We use char because int might match the return type of a gcc2
+   builtin and then its argument prototype would still apply.  */
+char $ac_func ();
+/* The GNU C library defines this for functions which it implements
+    to always fail with ENOSYS.  Some functions are actually named
+    something starting with __ and the normal name is an alias.  */
+#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+choke me
+#else
+char (*f) () = $ac_func;
+#endif
+#ifdef __cplusplus
+}
+#endif
+
+int
+main ()
+{
+return f != $ac_func;
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  eval "$as_ac_var=yes"
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+eval "$as_ac_var=no"
+fi
+rm -f conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+fi
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_var'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_var'}'`" >&6
+if test `eval echo '${'$as_ac_var'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_func" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+done
+
+    if test $tcl_corefoundation = yes; then
+
+for ac_header in libkern/OSAtomic.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
+  echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+fi
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+else
+  # Is the header compilable?
+echo "$as_me:$LINENO: checking $ac_header usability" >&5
+echo $ECHO_N "checking $ac_header usability... $ECHO_C" >&6
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+$ac_includes_default
+#include <$ac_header>
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_header_compiler=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_header_compiler=no
+fi
+rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+echo "$as_me:$LINENO: result: $ac_header_compiler" >&5
+echo "${ECHO_T}$ac_header_compiler" >&6
+
+# Is the header present?
+echo "$as_me:$LINENO: checking $ac_header presence" >&5
+echo $ECHO_N "checking $ac_header presence... $ECHO_C" >&6
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <$ac_header>
+_ACEOF
+if { (eval echo "$as_me:$LINENO: \"$ac_cpp conftest.$ac_ext\"") >&5
+  (eval $ac_cpp conftest.$ac_ext) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } >/dev/null; then
+  if test -s conftest.err; then
+    ac_cpp_err=$ac_c_preproc_warn_flag
+    ac_cpp_err=$ac_cpp_err$ac_c_werror_flag
+  else
+    ac_cpp_err=
+  fi
+else
+  ac_cpp_err=yes
+fi
+if test -z "$ac_cpp_err"; then
+  ac_header_preproc=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+  ac_header_preproc=no
+fi
+rm -f conftest.err conftest.$ac_ext
+echo "$as_me:$LINENO: result: $ac_header_preproc" >&5
+echo "${ECHO_T}$ac_header_preproc" >&6
+
+# So?  What about this header?
+case $ac_header_compiler:$ac_header_preproc:$ac_c_preproc_warn_flag in
+  yes:no: )
+    { echo "$as_me:$LINENO: WARNING: $ac_header: accepted by the compiler, rejected by the preprocessor!" >&5
+echo "$as_me: WARNING: $ac_header: accepted by the compiler, rejected by the preprocessor!" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header: proceeding with the compiler's result" >&5
+echo "$as_me: WARNING: $ac_header: proceeding with the compiler's result" >&2;}
+    ac_header_preproc=yes
+    ;;
+  no:yes:* )
+    { echo "$as_me:$LINENO: WARNING: $ac_header: present but cannot be compiled" >&5
+echo "$as_me: WARNING: $ac_header: present but cannot be compiled" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header:     check for missing prerequisite headers?" >&5
+echo "$as_me: WARNING: $ac_header:     check for missing prerequisite headers?" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header: see the Autoconf documentation" >&5
+echo "$as_me: WARNING: $ac_header: see the Autoconf documentation" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header:     section \"Present But Cannot Be Compiled\"" >&5
+echo "$as_me: WARNING: $ac_header:     section \"Present But Cannot Be Compiled\"" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header: proceeding with the preprocessor's result" >&5
+echo "$as_me: WARNING: $ac_header: proceeding with the preprocessor's result" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header: in the future, the compiler will take precedence" >&5
+echo "$as_me: WARNING: $ac_header: in the future, the compiler will take precedence" >&2;}
+    (
+      cat <<\_ASBOX
+## ------------------------------ ##
+## Report this to the tcl lists.  ##
+## ------------------------------ ##
+_ASBOX
+    ) |
+      sed "s/^/$as_me: WARNING:     /" >&2
+    ;;
+esac
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  eval "$as_ac_Header=\$ac_header_preproc"
+fi
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+
+fi
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+
+done
+
+
+for ac_func in OSSpinLockLock
+do
+as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_func" >&5
+echo $ECHO_N "checking for $ac_func... $ECHO_C" >&6
+if eval "test \"\${$as_ac_var+set}\" = set"; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+/* Define $ac_func to an innocuous variant, in case <limits.h> declares $ac_func.
+   For example, HP-UX 11i <limits.h> declares gettimeofday.  */
+#define $ac_func innocuous_$ac_func
+
+/* System header to define __stub macros and hopefully few prototypes,
+    which can conflict with char $ac_func (); below.
+    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
+    <limits.h> exists even on freestanding compilers.  */
+
+#ifdef __STDC__
+# include <limits.h>
+#else
+# include <assert.h>
+#endif
+
+#undef $ac_func
+
+/* Override any gcc2 internal prototype to avoid an error.  */
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+/* We use char because int might match the return type of a gcc2
+   builtin and then its argument prototype would still apply.  */
+char $ac_func ();
+/* The GNU C library defines this for functions which it implements
+    to always fail with ENOSYS.  Some functions are actually named
+    something starting with __ and the normal name is an alias.  */
+#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+choke me
+#else
+char (*f) () = $ac_func;
+#endif
+#ifdef __cplusplus
+}
+#endif
+
+int
+main ()
+{
+return f != $ac_func;
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  eval "$as_ac_var=yes"
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+eval "$as_ac_var=no"
+fi
+rm -f conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+fi
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_var'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_var'}'`" >&6
+if test `eval echo '${'$as_ac_var'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_func" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+done
+
+
+for ac_func in pthread_atfork
+do
+as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
+echo "$as_me:$LINENO: checking for $ac_func" >&5
+echo $ECHO_N "checking for $ac_func... $ECHO_C" >&6
+if eval "test \"\${$as_ac_var+set}\" = set"; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+/* Define $ac_func to an innocuous variant, in case <limits.h> declares $ac_func.
+   For example, HP-UX 11i <limits.h> declares gettimeofday.  */
+#define $ac_func innocuous_$ac_func
+
+/* System header to define __stub macros and hopefully few prototypes,
+    which can conflict with char $ac_func (); below.
+    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
+    <limits.h> exists even on freestanding compilers.  */
+
+#ifdef __STDC__
+# include <limits.h>
+#else
+# include <assert.h>
+#endif
+
+#undef $ac_func
+
+/* Override any gcc2 internal prototype to avoid an error.  */
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+/* We use char because int might match the return type of a gcc2
+   builtin and then its argument prototype would still apply.  */
+char $ac_func ();
+/* The GNU C library defines this for functions which it implements
+    to always fail with ENOSYS.  Some functions are actually named
+    something starting with __ and the normal name is an alias.  */
+#if defined (__stub_$ac_func) || defined (__stub___$ac_func)
+choke me
+#else
+char (*f) () = $ac_func;
+#endif
+#ifdef __cplusplus
+}
+#endif
+
+int
+main ()
+{
+return f != $ac_func;
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  eval "$as_ac_var=yes"
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+eval "$as_ac_var=no"
+fi
+rm -f conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+fi
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_var'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_var'}'`" >&6
+if test `eval echo '${'$as_ac_var'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_func" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+done
+
+    fi
+
+cat >>confdefs.h <<\_ACEOF
+#define USE_VFORK 1
+_ACEOF
+
+
+cat >>confdefs.h <<\_ACEOF
+#define TCL_DEFAULT_ENCODING "utf-8"
+_ACEOF
+
+
+cat >>confdefs.h <<\_ACEOF
+#define TCL_LOAD_FROM_MEMORY 1
+_ACEOF
+
+
+for ac_header in AvailabilityMacros.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
+  echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+fi
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+else
+  # Is the header compilable?
+echo "$as_me:$LINENO: checking $ac_header usability" >&5
+echo $ECHO_N "checking $ac_header usability... $ECHO_C" >&6
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+$ac_includes_default
+#include <$ac_header>
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_header_compiler=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_header_compiler=no
+fi
+rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+echo "$as_me:$LINENO: result: $ac_header_compiler" >&5
+echo "${ECHO_T}$ac_header_compiler" >&6
+
+# Is the header present?
+echo "$as_me:$LINENO: checking $ac_header presence" >&5
+echo $ECHO_N "checking $ac_header presence... $ECHO_C" >&6
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <$ac_header>
+_ACEOF
+if { (eval echo "$as_me:$LINENO: \"$ac_cpp conftest.$ac_ext\"") >&5
+  (eval $ac_cpp conftest.$ac_ext) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } >/dev/null; then
+  if test -s conftest.err; then
+    ac_cpp_err=$ac_c_preproc_warn_flag
+    ac_cpp_err=$ac_cpp_err$ac_c_werror_flag
+  else
+    ac_cpp_err=
+  fi
+else
+  ac_cpp_err=yes
+fi
+if test -z "$ac_cpp_err"; then
+  ac_header_preproc=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+  ac_header_preproc=no
+fi
+rm -f conftest.err conftest.$ac_ext
+echo "$as_me:$LINENO: result: $ac_header_preproc" >&5
+echo "${ECHO_T}$ac_header_preproc" >&6
+
+# So?  What about this header?
+case $ac_header_compiler:$ac_header_preproc:$ac_c_preproc_warn_flag in
+  yes:no: )
+    { echo "$as_me:$LINENO: WARNING: $ac_header: accepted by the compiler, rejected by the preprocessor!" >&5
+echo "$as_me: WARNING: $ac_header: accepted by the compiler, rejected by the preprocessor!" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header: proceeding with the compiler's result" >&5
+echo "$as_me: WARNING: $ac_header: proceeding with the compiler's result" >&2;}
+    ac_header_preproc=yes
+    ;;
+  no:yes:* )
+    { echo "$as_me:$LINENO: WARNING: $ac_header: present but cannot be compiled" >&5
+echo "$as_me: WARNING: $ac_header: present but cannot be compiled" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header:     check for missing prerequisite headers?" >&5
+echo "$as_me: WARNING: $ac_header:     check for missing prerequisite headers?" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header: see the Autoconf documentation" >&5
+echo "$as_me: WARNING: $ac_header: see the Autoconf documentation" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header:     section \"Present But Cannot Be Compiled\"" >&5
+echo "$as_me: WARNING: $ac_header:     section \"Present But Cannot Be Compiled\"" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header: proceeding with the preprocessor's result" >&5
+echo "$as_me: WARNING: $ac_header: proceeding with the preprocessor's result" >&2;}
+    { echo "$as_me:$LINENO: WARNING: $ac_header: in the future, the compiler will take precedence" >&5
+echo "$as_me: WARNING: $ac_header: in the future, the compiler will take precedence" >&2;}
+    (
+      cat <<\_ASBOX
+## ------------------------------ ##
+## Report this to the tcl lists.  ##
+## ------------------------------ ##
+_ASBOX
+    ) |
+      sed "s/^/$as_me: WARNING:     /" >&2
+    ;;
+esac
+echo "$as_me:$LINENO: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  eval "$as_ac_Header=\$ac_header_preproc"
+fi
+echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+
+fi
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+
+done
+
+    if test "$ac_cv_header_AvailabilityMacros_h" = yes; then
+	echo "$as_me:$LINENO: checking if weak import is available" >&5
+echo $ECHO_N "checking if weak import is available... $ECHO_C" >&6
+if test "${tcl_cv_cc_weak_import+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+
+	    hold_cflags=$CFLAGS; CFLAGS="$CFLAGS -Werror"
+	    cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+		    #ifdef __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__
+		    #if __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1020
+		    #error __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1020
+		    #endif
+		    #elif MAC_OS_X_VERSION_MIN_REQUIRED < 1020
+		    #error MAC_OS_X_VERSION_MIN_REQUIRED < 1020
+		    #endif
+		    int rand(void) __attribute__((weak_import));
+
+int
+main ()
+{
+rand();
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  tcl_cv_cc_weak_import=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+tcl_cv_cc_weak_import=no
+fi
+rm -f conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+	    CFLAGS=$hold_cflags
+fi
+echo "$as_me:$LINENO: result: $tcl_cv_cc_weak_import" >&5
+echo "${ECHO_T}$tcl_cv_cc_weak_import" >&6
+	if test $tcl_cv_cc_weak_import = yes; then
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_WEAK_IMPORT 1
+_ACEOF
+
+	fi
+    fi
+fi
+
 #--------------------------------------------------------------------
 # Check for support of fts functions (readdir replacement)
 #--------------------------------------------------------------------
@@ -14570,15 +14724,19 @@ _ACEOF
 cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
-#include <sys/param.h>
-            #include <sys/stat.h>
-            #include <fts.h>
+
+	    #include <sys/param.h>
+	    #include <sys/stat.h>
+	    #include <fts.h>
+
 int
 main ()
 {
-char*const p[2] = {"/", NULL};
-            FTS *f = fts_open(p, FTS_PHYSICAL|FTS_NOCHDIR|FTS_NOSTAT, NULL);
-            FTSENT *e = fts_read(f); fts_close(f);
+
+	    char*const p[2] = {"/", NULL};
+	    FTS *f = fts_open(p, FTS_PHYSICAL|FTS_NOCHDIR|FTS_NOSTAT, NULL);
+	    FTSENT *e = fts_read(f); fts_close(f);
+
   ;
   return 0;
 }
@@ -15001,6 +15159,8 @@ echo "${ECHO_T}O_NONBLOCK" >&6
 
 #------------------------------------------------------------------------
 
+echo "$as_me:$LINENO: checking whether to use dll unloading" >&5
+echo $ECHO_N "checking whether to use dll unloading... $ECHO_C" >&6
 # Check whether --enable-dll-unloading or --disable-dll-unloading was given.
 if test "${enable_dll_unloading+set}" = set; then
   enableval="$enable_dll_unloading"
@@ -15015,6 +15175,8 @@ cat >>confdefs.h <<\_ACEOF
 _ACEOF
 
 fi
+echo "$as_me:$LINENO: result: $tcl_ok" >&5
+echo "${ECHO_T}$tcl_ok" >&6
 
 #--------------------------------------------------------------------
 #	The statements below define a collection of symbols related to
@@ -15042,41 +15204,42 @@ HTML_DIR='$(DISTDIR)/html'
 
 if test "`uname -s`" = "Darwin" ; then
 
-    echo "$as_me:$LINENO: checking how to package libraries" >&5
+    if test "`uname -s`" = "Darwin" ; then
+	echo "$as_me:$LINENO: checking how to package libraries" >&5
 echo $ECHO_N "checking how to package libraries... $ECHO_C" >&6
-    # Check whether --enable-framework or --disable-framework was given.
+	# Check whether --enable-framework or --disable-framework was given.
 if test "${enable_framework+set}" = set; then
   enableval="$enable_framework"
-  tcl_ok=$enableval
+  enable_framework=$enableval
 else
-  tcl_ok=no
+  enable_framework=no
 fi;
-
-    if test "${enable_framework+set}" = set; then
-	enableval="$enable_framework"
-	tcl_ok=$enableval
-    else
-	tcl_ok=no
-    fi
-
-    if test "$tcl_ok" = "yes" ; then
-	echo "$as_me:$LINENO: result: framework" >&5
-echo "${ECHO_T}framework" >&6
-	FRAMEWORK_BUILD=1
-	if test "${SHARED_BUILD}" = "0" ; then
-	    { echo "$as_me:$LINENO: WARNING: Frameworks can only be built if --enable-shared is yes" >&5
+	if test $enable_framework = yes; then
+	    if test $SHARED_BUILD = 0; then
+		{ echo "$as_me:$LINENO: WARNING: Frameworks can only be built if --enable-shared is yes" >&5
 echo "$as_me: WARNING: Frameworks can only be built if --enable-shared is yes" >&2;}
-	    FRAMEWORK_BUILD=0
-	fi
-	if test $tcl_corefoundation = no; then
-	    { echo "$as_me:$LINENO: WARNING: Frameworks can only be used when CoreFoundation is available" >&5
+		enable_framework=no
+	    fi
+	    if test $tcl_corefoundation = no; then
+		{ echo "$as_me:$LINENO: WARNING: Frameworks can only be used when CoreFoundation is available" >&5
 echo "$as_me: WARNING: Frameworks can only be used when CoreFoundation is available" >&2;}
+		enable_framework=no
+	    fi
+	fi
+	if test $enable_framework = yes; then
+	    echo "$as_me:$LINENO: result: framework" >&5
+echo "${ECHO_T}framework" >&6
+	    FRAMEWORK_BUILD=1
+	else
+	    if test $SHARED_BUILD = 1; then
+		echo "$as_me:$LINENO: result: shared library" >&5
+echo "${ECHO_T}shared library" >&6
+	    else
+		echo "$as_me:$LINENO: result: static library" >&5
+echo "${ECHO_T}static library" >&6
+	    fi
 	    FRAMEWORK_BUILD=0
 	fi
-    else
-	echo "$as_me:$LINENO: result: standard shared library" >&5
-echo "${ECHO_T}standard shared library" >&6
-	FRAMEWORK_BUILD=0
     fi
 
     TCL_SHLIB_LD_EXTRAS="-compatibility_version ${TCL_VERSION} -current_version ${TCL_VERSION}`echo ${TCL_PATCH_LEVEL} | awk '{match($0, "\\\.[0-9]+"); print substr($0,RSTART,RLENGTH)}'`"
diff --git a/unix/configure.in b/unix/configure.in
index 1f082dc..3ffccf3 100644
--- a/unix/configure.in
+++ b/unix/configure.in
@@ -3,7 +3,7 @@ dnl	This file is an input file used by the GNU "autoconf" program to
 dnl	generate the file "configure", which is run during Tcl installation
 dnl	to configure the system for the local environment.
 #
-# RCS: @(#) $Id: configure.in,v 1.142 2006/05/04 14:01:27 dgp Exp $
+# RCS: @(#) $Id: configure.in,v 1.143 2006/07/20 06:18:38 das Exp $
 
 AC_INIT([tcl],[8.5])
 AC_PREREQ(2.59)
@@ -153,6 +153,13 @@ AC_CHECK_FUNC(strerror, , [AC_DEFINE(NO_STRERROR, 1, [Do we have strerror()])])
 AC_CHECK_FUNC(getwd, , [AC_DEFINE(NO_GETWD, 1, [Do we have getwd()])])
 AC_CHECK_FUNC(wait3, , [AC_DEFINE(NO_WAIT3, 1, [Do we have wait3()])])
 AC_CHECK_FUNC(uname, , [AC_DEFINE(NO_UNAME, 1, [Do we have uname()])])
+
+if test "`uname -s`" = "Darwin" && test "${TCL_THREADS}" = 1 && \
+	test "`uname -r | awk -F. '{print [$]1}'`" -lt 7; then
+    # prior to Darwin 7, realpath is not threadsafe, so don't
+    # use it when threads are enabled, c.f. bug # 711232
+    ac_cv_func_realpath=no
+fi
 AC_CHECK_FUNC(realpath, , [AC_DEFINE(NO_REALPATH, 1, [Do we have realpath()])])
 
 #---------------------------------------------------------------------------
@@ -173,14 +180,14 @@ SC_SERIAL_PORT
 #	special flag.
 #--------------------------------------------------------------------
 
-AC_CACHE_CHECK([for fd_set in sys/types], tcl_cv_type_fd_set,
+AC_CACHE_CHECK([for fd_set in sys/types], tcl_cv_type_fd_set, [
     AC_TRY_COMPILE([#include <sys/types.h>],[fd_set readMask, writeMask;],
-	tcl_cv_type_fd_set=yes, tcl_cv_type_fd_set=no))
+	tcl_cv_type_fd_set=yes, tcl_cv_type_fd_set=no)])
 tcl_ok=$tcl_cv_type_fd_set
 if test $tcl_ok = no; then
-    AC_CACHE_CHECK([for fd_mask in sys/select], tcl_cv_grep_fd_mask,
+    AC_CACHE_CHECK([for fd_mask in sys/select], tcl_cv_grep_fd_mask, [
 	AC_EGREP_HEADER(fd_mask, sys/select.h,
-	     tcl_cv_grep_fd_mask=present, tcl_cv_grep_fd_mask=missing))
+	     tcl_cv_grep_fd_mask=present, tcl_cv_grep_fd_mask=missing)])
     if test $tcl_cv_grep_fd_mask = present; then
 	AC_DEFINE(HAVE_SYS_SELECT_H, 1, [Should we include <sys/select.h>?])
 	tcl_ok=yes
@@ -270,8 +277,8 @@ AC_TYPE_PID_T
 AC_TYPE_SIZE_T
 AC_TYPE_UID_T
 
-AC_CACHE_CHECK([for socklen_t], ac_cv_type_socklen_t,
-    [AC_EGREP_CPP(changequote(<<,>>)dnl
+AC_CACHE_CHECK([for socklen_t], ac_cv_type_socklen_t, [
+    AC_EGREP_CPP(changequote(<<,>>)dnl
 <<(^|[^a-zA-Z_0-9])socklen_t[^a-zA-Z_0-9]>>dnl
 changequote([,]),[
     #include <sys/types.h>
@@ -302,13 +309,13 @@ AC_CHECK_FUNC(opendir, , [AC_DEFINE(USE_DIRENT2_H, 1, [May we include <dirent2.h
 #	the trick.
 #--------------------------------------------------------------------
 
-AC_CACHE_CHECK([union wait], tcl_cv_union_wait,
+AC_CACHE_CHECK([union wait], tcl_cv_union_wait, [
     AC_TRY_LINK([#include <sys/types.h> 
 #include <sys/wait.h>], [
 union wait x;
 WIFEXITED(x);		/* Generates compiler error if WIFEXITED
 			 * uses an int. */
-    ], tcl_cv_union_wait=yes, tcl_cv_union_wait=no))
+    ], tcl_cv_union_wait=yes, tcl_cv_union_wait=no)])
 if test $tcl_cv_union_wait = no; then
     AC_DEFINE(NO_UNION_WAIT, 1, [Do we have a usable 'union wait'?])
 fi
@@ -346,9 +353,9 @@ AC_CHECK_FUNC(BSDgettimeofday,
     [AC_DEFINE(HAVE_BSDGETTIMEOFDAY, 1, [Do we have BSDgettimeofday()?])], [
     AC_CHECK_FUNC(gettimeofday, , [AC_DEFINE(NO_GETTOD, 1, [Do we have gettimeofday()?])])
 ])
-AC_CACHE_CHECK([for gettimeofday declaration], tcl_cv_grep_gettimeofday,
+AC_CACHE_CHECK([for gettimeofday declaration], tcl_cv_grep_gettimeofday, [
     AC_EGREP_HEADER(gettimeofday, sys/time.h,
-	tcl_cv_grep_gettimeofday=present, tcl_cv_grep_gettimeofday=missing))
+	tcl_cv_grep_gettimeofday=present, tcl_cv_grep_gettimeofday=missing)])
 if test $tcl_cv_grep_gettimeofday = missing ; then
     AC_DEFINE(GETTOD_NOT_DECLARED, 1, [Is gettimeofday() actually declared in <sys/time.h>?])
 fi
@@ -360,11 +367,11 @@ fi
 #--------------------------------------------------------------------
 
 AC_C_CHAR_UNSIGNED
-AC_CACHE_CHECK([signed char declarations], tcl_cv_char_signed,
+AC_CACHE_CHECK([signed char declarations], tcl_cv_char_signed, [
     AC_TRY_COMPILE(, [
 	signed char *p;
 	p = 0;
-	], tcl_cv_char_signed=yes, tcl_cv_char_signed=no))
+	], tcl_cv_char_signed=yes, tcl_cv_char_signed=no)])
 if test $tcl_cv_char_signed = yes; then
     AC_DEFINE(HAVE_SIGNED_CHAR, 1, [Are characters signed?])
 fi
@@ -373,7 +380,7 @@ fi
 #  Does putenv() copy or not?  We need to know to avoid memory leaks.
 #--------------------------------------------------------------------
 
-AC_CACHE_CHECK([for a putenv() that copies the buffer], tcl_cv_putenv_copy,
+AC_CACHE_CHECK([for a putenv() that copies the buffer], tcl_cv_putenv_copy, [
     AC_TRY_RUN([
 	#include <stdlib.h>
 	#define OURVAR "havecopy=yes"
@@ -395,8 +402,7 @@ AC_CACHE_CHECK([for a putenv() that copies the buffer], tcl_cv_putenv_copy,
     ],
     tcl_cv_putenv_copy=no,
     tcl_cv_putenv_copy=yes,
-    tcl_cv_putenv_copy=no)
-)
+    tcl_cv_putenv_copy=no)])
 if test $tcl_cv_putenv_copy = yes; then
     AC_DEFINE(HAVE_PUTENV_THAT_COPIES, 1,
 	[Does putenv() copy strings or incorporate them by reference?])
@@ -415,23 +421,59 @@ SC_ENABLE_LANGINFO
 AC_CHECK_FUNCS(chflags)
 
 #--------------------------------------------------------------------
-# Check for support of getattrlist function (Darwin, HFS+)
+# Darwin specific API checks and defines
 #--------------------------------------------------------------------
 
-AC_CHECK_FUNCS(getattrlist)
+if test "`uname -s`" = "Darwin" ; then
+    AC_CHECK_FUNCS(getattrlist)
+    AC_CHECK_HEADERS(copyfile.h)
+    AC_CHECK_FUNCS(copyfile)
+    if test $tcl_corefoundation = yes; then
+	AC_CHECK_HEADERS(libkern/OSAtomic.h)
+	AC_CHECK_FUNCS(OSSpinLockLock)
+	AC_CHECK_FUNCS(pthread_atfork)
+    fi
+    AC_DEFINE(USE_VFORK, 1, [Should we use vfork() instead of fork()?])
+    AC_DEFINE(TCL_DEFAULT_ENCODING, "utf-8",
+	[Are we to override what our default encoding is?])
+    AC_DEFINE(TCL_LOAD_FROM_MEMORY, 1,
+	[Can this platform load code from memory?])
+    AC_CHECK_HEADERS(AvailabilityMacros.h)
+    if test "$ac_cv_header_AvailabilityMacros_h" = yes; then
+	AC_CACHE_CHECK([if weak import is available], tcl_cv_cc_weak_import, [
+	    hold_cflags=$CFLAGS; CFLAGS="$CFLAGS -Werror"
+	    AC_TRY_LINK([
+		    #ifdef __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__
+		    #if __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1020
+		    #error __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1020
+		    #endif
+		    #elif MAC_OS_X_VERSION_MIN_REQUIRED < 1020
+		    #error MAC_OS_X_VERSION_MIN_REQUIRED < 1020
+		    #endif
+		    int rand(void) __attribute__((weak_import));
+		], [rand();],
+		tcl_cv_cc_weak_import=yes, tcl_cv_cc_weak_import=no)
+	    CFLAGS=$hold_cflags])
+	if test $tcl_cv_cc_weak_import = yes; then
+	    AC_DEFINE(HAVE_WEAK_IMPORT, 1, [Is weak import available?])
+	fi
+    fi
+fi
 
 #--------------------------------------------------------------------
 # Check for support of fts functions (readdir replacement)
 #--------------------------------------------------------------------
 
 AC_CACHE_CHECK([for fts], tcl_cv_api_fts, [
-    AC_TRY_LINK([#include <sys/param.h>
-            #include <sys/stat.h>
-            #include <fts.h>], 
-        [char*const p[2] = {"/", NULL};
-            FTS *f = fts_open(p, FTS_PHYSICAL|FTS_NOCHDIR|FTS_NOSTAT, NULL);
-            FTSENT *e = fts_read(f); fts_close(f);], 
-        tcl_cv_api_fts=yes, tcl_cv_api_fts=no)])
+    AC_TRY_LINK([
+	    #include <sys/param.h>
+	    #include <sys/stat.h>
+	    #include <fts.h>
+	], [
+	    char*const p[2] = {"/", NULL};
+	    FTS *f = fts_open(p, FTS_PHYSICAL|FTS_NOCHDIR|FTS_NOSTAT, NULL);
+	    FTSENT *e = fts_read(f); fts_close(f);
+	], tcl_cv_api_fts=yes, tcl_cv_api_fts=no)])
 if test $tcl_cv_api_fts = yes; then
     AC_DEFINE(HAVE_FTS, 1, [Do we have fts functions?])
 fi
@@ -447,13 +489,15 @@ SC_BLOCKING_STYLE
 
 #------------------------------------------------------------------------
 
+AC_MSG_CHECKING([whether to use dll unloading])
 AC_ARG_ENABLE(dll-unloading,
     AC_HELP_STRING([--enable-dll-unloading],
-	[turn on the 'unload' command (default: on)]),
+	[enable the 'unload' command (default: on)]),
     [tcl_ok=$enableval], [tcl_ok=yes])
 if test $tcl_ok = yes; then
     AC_DEFINE(TCL_UNLOAD_DLLS, 1, [Do we allow unloading of shared libraries?])
 fi
+AC_MSG_RESULT([$tcl_ok])
 
 #--------------------------------------------------------------------
 #	The statements below define a collection of symbols related to
diff --git a/unix/tcl.m4 b/unix/tcl.m4
index 3b2e228..e009b9b 100644
--- a/unix/tcl.m4
+++ b/unix/tcl.m4
@@ -560,33 +560,33 @@ AC_DEFUN([SC_ENABLE_SHARED], [
 #------------------------------------------------------------------------
 
 AC_DEFUN([SC_ENABLE_FRAMEWORK], [
-    AC_MSG_CHECKING([how to package libraries])
-    AC_ARG_ENABLE(framework,
-	AC_HELP_STRING([--enable-framework],
-	    [package shared libraries in MacOSX frameworks (default: off)]),
-	[tcl_ok=$enableval], [tcl_ok=no])
-
-    if test "${enable_framework+set}" = set; then
-	enableval="$enable_framework"
-	tcl_ok=$enableval
-    else
-	tcl_ok=no
-    fi
-
-    if test "$tcl_ok" = "yes" ; then
-	AC_MSG_RESULT([framework])
-	FRAMEWORK_BUILD=1
-	if test "${SHARED_BUILD}" = "0" ; then
-	    AC_MSG_WARN([Frameworks can only be built if --enable-shared is yes])
-	    FRAMEWORK_BUILD=0
+    if test "`uname -s`" = "Darwin" ; then
+	AC_MSG_CHECKING([how to package libraries])
+	AC_ARG_ENABLE(framework,
+	    AC_HELP_STRING([--enable-framework],
+		[package shared libraries in MacOSX frameworks (default: off)]),
+	    [enable_framework=$enableval], [enable_framework=no])
+	if test $enable_framework = yes; then
+	    if test $SHARED_BUILD = 0; then
+		AC_MSG_WARN([Frameworks can only be built if --enable-shared is yes])
+		enable_framework=no
+	    fi
+	    if test $tcl_corefoundation = no; then
+		AC_MSG_WARN([Frameworks can only be used when CoreFoundation is available])
+		enable_framework=no
+	    fi
 	fi
-	if test $tcl_corefoundation = no; then
-	    AC_MSG_WARN([Frameworks can only be used when CoreFoundation is available])
+	if test $enable_framework = yes; then
+	    AC_MSG_RESULT([framework])
+	    FRAMEWORK_BUILD=1
+	else
+	    if test $SHARED_BUILD = 1; then
+		AC_MSG_RESULT([shared library])
+	    else
+		AC_MSG_RESULT([static library])
+	    fi
 	    FRAMEWORK_BUILD=0
 	fi
-    else
-	AC_MSG_RESULT([standard shared library])
-	FRAMEWORK_BUILD=0
     fi
 ])
 
@@ -683,10 +683,10 @@ AC_DEFUN([SC_ENABLE_THREADS], [
 	    AC_DEFINE(HAVE_PTHREAD_ATTR_GET_NP, 1,
 		[Do we want a BSD-like thread-attribute interface?])
 	    AC_CACHE_CHECK([for pthread_attr_get_np declaration],
-		tcl_cv_grep_pthread_attr_get_np,
+		tcl_cv_grep_pthread_attr_get_np, [
 		AC_EGREP_HEADER(pthread_attr_get_np, pthread.h,
 		    tcl_cv_grep_pthread_attr_get_np=present,
-		    tcl_cv_grep_pthread_attr_get_np=missing))
+		    tcl_cv_grep_pthread_attr_get_np=missing)])
 	    if test $tcl_cv_grep_pthread_attr_get_np = missing ; then
 		AC_DEFINE(ATTRGETNP_NOT_DECLARED, 1,
 		    [Is pthread_attr_get_np() declared in <pthread.h>?])
@@ -697,10 +697,10 @@ AC_DEFUN([SC_ENABLE_THREADS], [
 		AC_DEFINE(HAVE_PTHREAD_GETATTR_NP, 1,
 		    [Do we want a Linux-like thread-attribute interface?])
 		AC_CACHE_CHECK([for pthread_getattr_np declaration],
-		    tcl_cv_grep_pthread_getattr_np,
+		    tcl_cv_grep_pthread_getattr_np, [
 		    AC_EGREP_HEADER(pthread_getattr_np, pthread.h,
 			tcl_cv_grep_pthread_getattr_np=present,
-			tcl_cv_grep_pthread_getattr_np=missing))
+			tcl_cv_grep_pthread_getattr_np=missing)])
 		if test $tcl_cv_grep_pthread_getattr_np = missing ; then
 		    AC_DEFINE(GETATTRNP_NOT_DECLARED, 1,
 			[Is pthread_getattr_np declared in <pthread.h>?])
@@ -1596,7 +1596,7 @@ dnl AC_CHECK_TOOL(AR, ar)
 	    AC_MSG_CHECKING([whether to use CoreFoundation])
 	    AC_ARG_ENABLE(corefoundation,
 		AC_HELP_STRING([--enable-corefoundation],
-		    [use CoreFoundation API on MacOSX (default: yes)]),
+		    [use CoreFoundation API on MacOSX (default: on)]),
 		[tcl_corefoundation=$enableval], [tcl_corefoundation=yes])
 	    AC_MSG_RESULT([$tcl_corefoundation])
 	    if test $tcl_corefoundation = yes; then
@@ -1616,29 +1616,14 @@ dnl AC_CHECK_TOOL(AR, ar)
 		if test $tcl_cv_lib_corefoundation = yes; then
 		    LIBS="$LIBS -framework CoreFoundation"
 		    AC_DEFINE(HAVE_COREFOUNDATION, 1, 
-			[Do we have access to Darwin CoreFoundation.framework ?])
-		    AC_CHECK_HEADERS(libkern/OSAtomic.h)
-		    AC_CHECK_FUNCS(OSSpinLockLock)
-		    AC_CHECK_FUNCS(pthread_atfork)
+			[Do we have access to Darwin CoreFoundation.framework?])
+		else
+		    tcl_corefoundation=no
 		fi
 	    fi
-	    AC_CHECK_HEADERS(copyfile.h)
-	    AC_CHECK_FUNCS(copyfile)
 	    AC_DEFINE(MAC_OSX_TCL, 1, [Is this a Mac I see before me?])
-	    AC_DEFINE(USE_VFORK, 1, [Should we use vfork() instead of fork()?])
-	    AC_DEFINE(TCL_DEFAULT_ENCODING, "utf-8",
-		[Are we to override what our default encoding is?])
 	    AC_DEFINE(MODULE_SCOPE, __private_extern__,
 		[Linker support for module scope symbols])
-	    AC_DEFINE(TCL_LOAD_FROM_MEMORY, 1,
-		[Can this platform load code from memory?])
-	    # prior to Darwin 7, realpath is not threadsafe, so don't
-	    # use it when threads are enabled, c.f. bug # 711232:
-	    AC_CHECK_FUNC(realpath)
-	    if test $ac_cv_func_realpath = yes -a "${TCL_THREADS}" = 1 \
-		    -a `uname -r | awk -F. '{print [$]1}'` -lt 7 ; then
-		ac_cv_func_realpath=no
-	    fi
 	    ;;
 	NEXTSTEP-*)
 	    SHLIB_CFLAGS=""
@@ -1912,8 +1897,8 @@ dnl AC_CHECK_TOOL(AR, ar)
     # Step 4: disable dynamic loading if requested via a command-line switch.
 
     AC_ARG_ENABLE(load,
-	AC_HELP_STRING([--disable-load],
-	    [disallow dynamic loading and "load" command (default: enabled)]),
+	AC_HELP_STRING([--enable-load],
+	    [allow dynamic loading and "load" command (default: on)]),
 	[tcl_ok=$enableval], [tcl_ok=yes])
     if test "$tcl_ok" = "no"; then
 	DL_OBJS=""
@@ -2202,7 +2187,7 @@ int main() {
 #--------------------------------------------------------------------
 
 AC_DEFUN([SC_MISSING_POSIX_HEADERS], [
-    AC_CACHE_CHECK([dirent.h], tcl_cv_dirent_h,
+    AC_CACHE_CHECK([dirent.h], tcl_cv_dirent_h, [
     AC_TRY_LINK([#include <sys/types.h>
 #include <dirent.h>], [
 #ifndef _POSIX_SOURCE
@@ -2222,7 +2207,7 @@ d = opendir("foobar");
 entryPtr = readdir(d);
 p = entryPtr->d_name;
 closedir(d);
-], tcl_cv_dirent_h=yes, tcl_cv_dirent_h=no))
+], tcl_cv_dirent_h=yes, tcl_cv_dirent_h=no)])
 
     if test $tcl_cv_dirent_h = no; then
 	AC_DEFINE(NO_DIRENT_H, 1, [Do we have <dirent.h>?])
@@ -2416,16 +2401,16 @@ AC_DEFUN([SC_TIME_HANDLER], [
 
     AC_CHECK_FUNCS(gmtime_r localtime_r mktime)
 
-    AC_CACHE_CHECK([tm_tzadj in struct tm], tcl_cv_member_tm_tzadj,
+    AC_CACHE_CHECK([tm_tzadj in struct tm], tcl_cv_member_tm_tzadj, [
 	AC_TRY_COMPILE([#include <time.h>], [struct tm tm; tm.tm_tzadj;],
-	    tcl_cv_member_tm_tzadj=yes, tcl_cv_member_tm_tzadj=no))
+	    tcl_cv_member_tm_tzadj=yes, tcl_cv_member_tm_tzadj=no)])
     if test $tcl_cv_member_tm_tzadj = yes ; then
 	AC_DEFINE(HAVE_TM_TZADJ, 1, [Should we use the tm_tzadj field of struct tm?])
     fi
 
-    AC_CACHE_CHECK([tm_gmtoff in struct tm], tcl_cv_member_tm_gmtoff,
+    AC_CACHE_CHECK([tm_gmtoff in struct tm], tcl_cv_member_tm_gmtoff, [
 	AC_TRY_COMPILE([#include <time.h>], [struct tm tm; tm.tm_gmtoff;],
-	    tcl_cv_member_tm_gmtoff=yes, tcl_cv_member_tm_gmtoff=no))
+	    tcl_cv_member_tm_gmtoff=yes, tcl_cv_member_tm_gmtoff=no)])
     if test $tcl_cv_member_tm_gmtoff = yes ; then
 	AC_DEFINE(HAVE_TM_GMTOFF, 1, [Should we use the tm_gmtoff field of struct tm?])
     fi
@@ -2434,24 +2419,24 @@ AC_DEFUN([SC_TIME_HANDLER], [
     # Its important to include time.h in this check, as some systems
     # (like convex) have timezone functions, etc.
     #
-    AC_CACHE_CHECK([long timezone variable], tcl_cv_timezone_long,
+    AC_CACHE_CHECK([long timezone variable], tcl_cv_timezone_long, [
 	AC_TRY_COMPILE([#include <time.h>],
 	    [extern long timezone;
 	    timezone += 1;
 	    exit (0);],
-	    tcl_cv_timezone_long=yes, tcl_cv_timezone_long=no))
+	    tcl_cv_timezone_long=yes, tcl_cv_timezone_long=no)])
     if test $tcl_cv_timezone_long = yes ; then
 	AC_DEFINE(HAVE_TIMEZONE_VAR, 1, [Should we use the global timezone variable?])
     else
 	#
 	# On some systems (eg IRIX 6.2), timezone is a time_t and not a long.
 	#
-	AC_CACHE_CHECK([time_t timezone variable], tcl_cv_timezone_time,
+	AC_CACHE_CHECK([time_t timezone variable], tcl_cv_timezone_time, [
 	    AC_TRY_COMPILE([#include <time.h>],
 		[extern time_t timezone;
 		timezone += 1;
 		exit (0);],
-		tcl_cv_timezone_time=yes, tcl_cv_timezone_time=no))
+		tcl_cv_timezone_time=yes, tcl_cv_timezone_time=no)])
 	if test $tcl_cv_timezone_time = yes ; then
 	    AC_DEFINE(HAVE_TIMEZONE_VAR, 1, [Should we use the global timezone variable?])
 	fi
diff --git a/unix/tclConfig.h.in b/unix/tclConfig.h.in
index 2e3d21f..28962b8 100644
--- a/unix/tclConfig.h.in
+++ b/unix/tclConfig.h.in
@@ -13,6 +13,9 @@
 /* Is gettimeofday() actually declared in <sys/time.h>? */
 #undef GETTOD_NOT_DECLARED
 
+/* Define to 1 if you have the <AvailabilityMacros.h> header file. */
+#undef HAVE_AVAILABILITYMACROS_H
+
 /* Do we have BSDgettimeofday()? */
 #undef HAVE_BSDGETTIMEOFDAY
 
@@ -25,7 +28,7 @@
 /* Define to 1 if you have the <copyfile.h> header file. */
 #undef HAVE_COPYFILE_H
 
-/* Do we have access to Darwin CoreFoundation.framework ? */
+/* Do we have access to Darwin CoreFoundation.framework? */
 #undef HAVE_COREFOUNDATION
 
 /* Do we have fts functions? */
@@ -184,6 +187,9 @@
 /* Define to 1 if you have the `waitpid' function. */
 #undef HAVE_WAITPID
 
+/* Is weak import available? */
+#undef HAVE_WEAK_IMPORT
+
 /* Is this a Mac I see before me? */
 #undef MAC_OSX_TCL
 
diff --git a/unix/tclLoadDyld.c b/unix/tclLoadDyld.c
index 81f59be..332c6c1 100644
--- a/unix/tclLoadDyld.c
+++ b/unix/tclLoadDyld.c
@@ -12,7 +12,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclLoadDyld.c,v 1.23 2006/03/16 09:15:43 das Exp $
+ * RCS: @(#) $Id: tclLoadDyld.c,v 1.24 2006/07/20 06:18:38 das Exp $
  */
 
 #include "tclInt.h"
@@ -34,11 +34,7 @@ typedef struct Tcl_DyldLoadHandle {
 } Tcl_DyldLoadHandle;
 
 #ifdef TCL_LOAD_FROM_MEMORY
-typedef struct ThreadSpecificData {
-    int haveLoadMemory;
-} ThreadSpecificData;
-
-static Tcl_ThreadDataKey dataKey;
+MODULE_SCOPE long tclMacOSXDarwinRelease;
 #endif
 
 /*
@@ -389,23 +385,13 @@ TclpLoadMemoryGetBuffer(
     Tcl_Interp *interp,		/* Used for error reporting. */
     int size)			/* Size of desired buffer. */
 {
-    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
     void *buffer = NULL;
 
-    if (!tsdPtr->haveLoadMemory) {
-	/*
-	 * NSCreateObjectFileImageFromMemory is available but always fails
-	 * prior to Darwin 7.
-	 */
-
-	struct utsname name;
-
-	if (!uname(&name)) {
-	    long release = strtol(name.release, NULL, 10);
-	    tsdPtr->haveLoadMemory = (release >= 7) ? 1 : -1;
-	}
-    }
-    if (tsdPtr->haveLoadMemory > 0) {
+    /*
+     * NSCreateObjectFileImageFromMemory is available but always fails
+     * prior to Darwin 7.
+     */
+    if (tclMacOSXDarwinRelease >= 7) {
 	/*
 	 * We must allocate the buffer using vm_allocate, because
 	 * NSCreateObjectFileImageFromMemory will dispose of it using
@@ -478,14 +464,14 @@ TclpLoadMemory(
 	#define mh_size  sizeof(struct mach_header_64)
 #endif
 	
-	if (codeSize >= sizeof(struct fat_header)
+	if ((size_t) codeSize >= sizeof(struct fat_header)
 		&& fh->magic == OSSwapHostToBigInt32(FAT_MAGIC)) {
 	    /*
 	     * Fat binary, try to find mach_header for our architecture
 	     */
 	    uint32_t fh_nfat_arch = OSSwapBigToHostInt32(fh->nfat_arch);
 	    
-	    if (codeSize >= sizeof(struct fat_header) + 
+	    if ((size_t) codeSize >= sizeof(struct fat_header) + 
 		    fh_nfat_arch * sizeof(struct fat_arch)) {
 		void *fatarchs = buffer + sizeof(struct fat_header);
 		CONST NXArchInfo *arch = NXGetLocalArchInfo();
diff --git a/unix/tclUnixFCmd.c b/unix/tclUnixFCmd.c
index 1bba9ee..27b880e 100644
--- a/unix/tclUnixFCmd.c
+++ b/unix/tclUnixFCmd.c
@@ -10,7 +10,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclUnixFCmd.c,v 1.53 2006/03/28 10:45:25 das Exp $
+ * RCS: @(#) $Id: tclUnixFCmd.c,v 1.54 2006/07/20 06:18:38 das Exp $
  *
  * Portions of this code were derived from NetBSD source code which has the
  * following copyright notice:
@@ -218,6 +218,22 @@ Realpath(
 #else
 #define Realpath realpath
 #endif
+
+#ifndef NO_REALPATH
+#if defined(__APPLE__) && defined(TCL_THREADS) && \
+	defined(MAC_OS_X_VERSION_MIN_REQUIRED) && \
+	MAC_OS_X_VERSION_MIN_REQUIRED < 1030
+/*
+ * prior to Darwin 7, realpath is not threadsafe, c.f. bug 711232;
+ * if we might potentially be running on pre-10.3 OSX,
+ * check Darwin release at runtime before using realpath.
+ */
+MODULE_SCOPE long tclMacOSXDarwinRelease;
+#define haveRealpath (tclMacOSXDarwinRelease >= 7)
+#else
+#define haveRealpath 1
+#endif
+#endif /* NO_REALPATH */
 
 /*
  *---------------------------------------------------------------------------
@@ -294,7 +310,7 @@ DoRenameFile(
      * compiled because realpath() not defined on all systems.
      */
 
-    if (errno == EINVAL) {
+    if (errno == EINVAL && haveRealpath) {
 	char srcPath[MAXPATHLEN], dstPath[MAXPATHLEN];
 	DIR *dirPtr;
 	Tcl_DirEntry *dirEntPtr;
@@ -1877,7 +1893,7 @@ TclpObjNormalizePath(
      * For speed, try to get the entire path in one go.
      */
 
-    if (nextCheckpoint == 0) {
+    if (nextCheckpoint == 0 && haveRealpath) {
 	char *lastDir = strrchr(currentPathEndPosition, '/');
 
 	if (lastDir != NULL) {
@@ -1950,86 +1966,88 @@ TclpObjNormalizePath(
      */
 
 #ifndef NO_REALPATH
-    /*
-     * If we only had '/foo' or '/' then we never increment nextCheckpoint and
-     * we don't need or want to go through 'Realpath'. Also, on some
-     * platforms, passing an empty string to 'Realpath' will give us the
-     * normalized pwd, which is not what we want at all!
-     */
+    if (haveRealpath) {
+	/*
+	 * If we only had '/foo' or '/' then we never increment nextCheckpoint
+	 * and we don't need or want to go through 'Realpath'. Also, on some
+	 * platforms, passing an empty string to 'Realpath' will give us the
+	 * normalized pwd, which is not what we want at all!
+	 */
 
-    if (nextCheckpoint == 0) {
-	return 0;
-    }
+	if (nextCheckpoint == 0) {
+	    return 0;
+	}
 
-    nativePath = Tcl_UtfToExternalDString(NULL, path, nextCheckpoint, &ds);
-    if (Realpath(nativePath, normPath) != NULL) {
-	int newNormLen;
+	nativePath = Tcl_UtfToExternalDString(NULL, path, nextCheckpoint, &ds);
+	if (Realpath(nativePath, normPath) != NULL) {
+	    int newNormLen;
 
-    wholeStringOk:
-	newNormLen = strlen(normPath);
-	if ((newNormLen == Tcl_DStringLength(&ds))
-		&& (strcmp(normPath, nativePath) == 0)) {
-	    /*
-	     * String is unchanged.
-	     */
+	wholeStringOk:
+	    newNormLen = strlen(normPath);
+	    if ((newNormLen == Tcl_DStringLength(&ds))
+		    && (strcmp(normPath, nativePath) == 0)) {
+		/*
+		 * String is unchanged.
+		 */
 
-	    Tcl_DStringFree(&ds);
+		Tcl_DStringFree(&ds);
 
-	    /*
-	     * Enable this to have the native FS claim normalization of the
-	     * whole path for existing files. That would permit the caller to
-	     * declare normalization complete without calls to additional
-	     * filesystems. Saving lots of calls is probably worth the extra
-	     * access() time here. When no other FS's are registered though,
-	     * things are less clear.
-	     *
-	    if (0 == access(normPath, F_OK)) {
-		return pathLen;
+		/*
+		 * Enable this to have the native FS claim normalization of the
+		 * whole path for existing files. That would permit the caller
+		 * to declare normalization complete without calls to additional
+		 * filesystems. Saving lots of calls is probably worth the extra
+		 * access() time here. When no other FS's are registered though,
+		 * things are less clear.
+		 *
+		if (0 == access(normPath, F_OK)) {
+		    return pathLen;
+		}
+		 */
+
+		return nextCheckpoint;
 	    }
+
+	    /*
+	     * Free up the native path and put in its place the converted,
+	     * normalized path.
 	     */
 
-	    return nextCheckpoint;
-	}
+	    Tcl_DStringFree(&ds);
+	    Tcl_ExternalToUtfDString(NULL, normPath, (int) newNormLen, &ds);
 
-	/*
-	 * Free up the native path and put in its place the converted,
-	 * normalized path.
-	 */
+	    if (path[nextCheckpoint] != '\0') {
+		/*
+		 * Not at end, append remaining path.
+		 */
 
-	Tcl_DStringFree(&ds);
-	Tcl_ExternalToUtfDString(NULL, normPath, (int) newNormLen, &ds);
+		int normLen = Tcl_DStringLength(&ds);
 
-	if (path[nextCheckpoint] != '\0') {
-	    /*
-	     * Not at end, append remaining path.
-	     */
+		Tcl_DStringAppend(&ds, path + nextCheckpoint,
+			pathLen - nextCheckpoint);
 
-	    int normLen = Tcl_DStringLength(&ds);
+		/*
+		 * We recognise up to and including the directory separator.
+		 */
 
-	    Tcl_DStringAppend(&ds, path + nextCheckpoint,
-		    pathLen - nextCheckpoint);
+		nextCheckpoint = normLen + 1;
+	    } else {
+		/*
+		 * We recognise the whole string.
+		 */
 
-	    /*
-	     * We recognise up to and including the directory separator.
-	     */
+		nextCheckpoint = Tcl_DStringLength(&ds);
+	    }
 
-	    nextCheckpoint = normLen + 1;
-	} else {
 	    /*
-	     * We recognise the whole string.
+	     * Overwrite with the normalized path.
 	     */
 
-	    nextCheckpoint = Tcl_DStringLength(&ds);
+	    Tcl_SetStringObj(pathPtr, Tcl_DStringValue(&ds),
+		    Tcl_DStringLength(&ds));
 	}
-
-	/*
-	 * Overwrite with the normalized path.
-	 */
-
-	Tcl_SetStringObj(pathPtr, Tcl_DStringValue(&ds),
-		Tcl_DStringLength(&ds));
+	Tcl_DStringFree(&ds);
     }
-    Tcl_DStringFree(&ds);
 #endif	/* !NO_REALPATH */
 
     return nextCheckpoint;
diff --git a/unix/tclUnixInit.c b/unix/tclUnixInit.c
index 71bd1bb..cffcc6c 100644
--- a/unix/tclUnixInit.c
+++ b/unix/tclUnixInit.c
@@ -7,14 +7,21 @@
  * Copyright (c) 1999 by Scriptics Corporation.
  * All rights reserved.
  *
- * RCS: @(#) $Id: tclUnixInit.c,v 1.63 2006/02/08 21:41:28 dgp Exp $
+ * RCS: @(#) $Id: tclUnixInit.c,v 1.64 2006/07/20 06:18:38 das Exp $
  */
 
 #include "tclInt.h"
 #include <stddef.h>
 #include <locale.h>
 #ifdef HAVE_LANGINFO
-#include <langinfo.h>
+#   include <langinfo.h>
+#   ifdef __APPLE__
+#       if defined(HAVE_WEAK_IMPORT) && MAC_OS_X_VERSION_MIN_REQUIRED < 1030
+	    /* Support for weakly importing nl_langinfo on Darwin. */
+#           define WEAK_IMPORT_NL_LANGINFO
+	    extern char *nl_langinfo(nl_item) WEAK_IMPORT_ATTRIBUTE;
+#       endif
+#    endif
 #endif
 #include <sys/resource.h>
 #if defined(__FreeBSD__) && defined(__GNUC__)
@@ -331,6 +338,17 @@ static int		GetStackSize(size_t *stackSizePtr);
 static int		MacOSXGetLibraryPath(Tcl_Interp *interp,
 			    int maxPathLen, char *tclLibPath);
 #endif /* HAVE_COREFOUNDATION */
+#if defined(__APPLE__) && (defined(TCL_LOAD_FROM_MEMORY) || ( \
+	defined(TCL_THREADS) && defined(MAC_OS_X_VERSION_MIN_REQUIRED) && \
+	MAC_OS_X_VERSION_MIN_REQUIRED < 1030))
+/*
+ * Need to check Darwin release at runtime in tclUnixFCmd.c and tclLoadDyld.c:
+ * initialize release global at startup from uname().
+ */
+#define GET_DARWIN_RELEASE 1
+MODULE_SCOPE long tclMacOSXDarwinRelease;
+long tclMacOSXDarwinRelease = 0;
+#endif
 
 /*
  *---------------------------------------------------------------------------
@@ -425,6 +443,15 @@ TclpInitPlatform(void)
      */
 
     setlocale(LC_NUMERIC, "C");
+
+#ifdef GET_DARWIN_RELEASE
+    {
+	struct utsname name;
+	if (!uname(&name)) {
+	    tclMacOSXDarwinRelease = strtol(name.release, NULL, 10);
+	}
+    }
+#endif
 }
 
 /*
@@ -620,7 +647,11 @@ Tcl_GetEncodingNameFromEnvironment(
      */
 
 #ifdef HAVE_LANGINFO
-    if (setlocale(LC_CTYPE, "") != NULL) {
+    if (
+#ifdef WEAK_IMPORT_NL_LANGINFO
+	    nl_langinfo != NULL &&
+#endif
+	    setlocale(LC_CTYPE, "") != NULL) {
 	Tcl_DString ds;
 
 	/*
diff --git a/unix/tclUnixPort.h b/unix/tclUnixPort.h
index 62100c3..652aa83 100644
--- a/unix/tclUnixPort.h
+++ b/unix/tclUnixPort.h
@@ -19,7 +19,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclUnixPort.h,v 1.48 2006/07/14 16:28:50 andreas_kupries Exp $
+ * RCS: @(#) $Id: tclUnixPort.h,v 1.49 2006/07/20 06:18:38 das Exp $
  */
 
 #ifndef _TCLUNIXPORT
@@ -506,11 +506,6 @@ extern double strtod();
  */
 
 #ifdef __APPLE__
-/*
- * Translate the symbolic values for MAC_OS_X_VERSION_MAX_ALLOWED to
- * the numbers used in the comparisons below.
- */
-#include <AvailabilityMacros.h>
 /* 
  * Support for fat compiles: configure runs only once for multiple architectures
  */
@@ -528,6 +523,25 @@ extern double strtod();
 #       undef USE_TERMIO
 #       undef USE_SGTTY
 #   endif /* __DARWIN_UNIX03 */
+/* 
+ * Include AvailabilityMacros.h here (when available) to ensure any symbolic
+ * MAC_OS_X_VERSION_* constants passed on the command line are translated.
+ */
+#   ifdef HAVE_AVAILABILITYMACROS_H
+#       include <AvailabilityMacros.h>
+#   endif
+/* 
+ * Support for weak import.
+ */
+#   ifdef HAVE_WEAK_IMPORT
+#       if !defined(HAVE_AVAILABILITYMACROS_H) || !defined(MAC_OS_X_VERSION_MIN_REQUIRED)
+#           undef HAVE_WEAK_IMPORT
+#       else
+#           ifndef WEAK_IMPORT_ATTRIBUTE
+#               define WEAK_IMPORT_ATTRIBUTE __attribute__((weak_import))
+#           endif
+#       endif
+#   endif /* HAVE_WEAK_IMPORT */
 /*
  * Support for MAC_OS_X_VERSION_MAX_ALLOWED define from AvailabilityMacros.h:
  * only use API available in the indicated OS version or earlier.
@@ -539,7 +553,10 @@ extern double strtod();
 #           undef HAVE_COPYFILE
 #       endif
 #       if MAC_OS_X_VERSION_MAX_ALLOWED < 1030
-#           define NO_REALPATH 1
+#           ifdef TCL_THREADS
+		/* prior to 10.3, realpath is not threadsafe, c.f. bug 711232 */
+#               define NO_REALPATH 1
+#           endif
 #           undef HAVE_LANGINFO
 #       endif
 #   endif /* MAC_OS_X_VERSION_MAX_ALLOWED */