Merged the workarounds and fixes for wrapped executables on various

platforms into the trunk. For details see the merged revision and its
ancestor.

1 files changed, 85 insertions, 1 deletions

diff --git a/generic/tclIOUtil.c b/generic/tclIOUtil.c
index f624cb7..d2919fc 100644
--- a/generic/tclIOUtil.c
+++ b/generic/tclIOUtil.c
@@ -24,6 +24,12 @@
 #endif
 #include "tclFileSystem.h"
 
+#ifdef TCL_TEMPLOAD_NO_UNLINK
+#ifndef NO_FSTATFS
+#include <sys/statfs.h>
+#endif
+#endif
+
 /*
  * struct FilesystemRecord --
  *
@@ -3110,6 +3116,82 @@ Tcl_FSLoadFile(
  *----------------------------------------------------------------------
  */
 
+/*
+ * Workaround for issue with modern HPUX which do allow the unlink (no ETXTBSY
+ * error) yet somehow trash some internal data structures which prevents the
+ * second and further shared libraries from getting properly loaded. Only the
+ * first is ok. We try to get around the issue by not unlinking,
+ * i.e. emulating the behaviour of the older HPUX which denied removal.
+ *
+ * Doing the unlink is also an issue within docker containers, whose AUFS
+ * bungles this as well, see
+ *     https://github.com/dotcloud/docker/issues/1911
+ *
+ * For these situations the change below makes the execution of the unlink
+ * semi-controllable at runtime.
+ *
+ *     An AUFS filesystem (if it can be detected) will force avoidance of
+ *     unlink. The env variable TCL_TEMPLOAD_NO_UNLINK allows detection of a
+ *     users general request (unlink and not.
+ *
+ * By default the unlink is done (if not in AUFS). However if the variable is
+ * present and set to true (any integer > 0) then the unlink is skipped.
+ */
+
+int
+TclSkipUnlink (Tcl_Obj* shlibFile)
+{
+    /* Order of testing:
+     * 1. On hpux we generally want to skip unlink in general
+     *
+     * Outside of hpux then:
+     * 2. For a general user request   (TCL_TEMPLOAD_NO_UNLINK present, non-empty, => int)
+     * 3. For general AUFS environment (statfs, if available).
+     *
+     * Ad 2: This variable can disable/override the AUFS detection, i.e. for
+     * testing if a newer AUFS does not have the bug any more.
+     * 
+     * Ad 3: This is conditionally compiled in. Condition currently must be set manually.
+     *       This part needs proper tests in the configure(.in).
+     */
+
+#ifdef hpux
+    return 1;
+#else
+    char* skipstr;
+
+    skipstr = getenv ("TCL_TEMPLOAD_NO_UNLINK");
+    if (skipstr && (skipstr[0] != '\0')) {
+	return atoi(skipstr);
+    }
+
+#ifdef TCL_TEMPLOAD_NO_UNLINK
+#ifndef NO_FSTATFS
+    {
+	struct statfs fs;
+	/* Have fstatfs. May not have the AUFS super magic ... Indeed our build
+	 * box is too old to have it directly in the headers. Define taken from
+	 *     http://mooon.googlecode.com/svn/trunk/linux_include/linux/aufs_type.h
+	 *     http://aufs.sourceforge.net/
+	 * Better reference will be gladly taken.
+	 */
+#ifndef AUFS_SUPER_MAGIC
+#define AUFS_SUPER_MAGIC ('a' << 24 | 'u' << 16 | 'f' << 8 | 's')
+#endif /* AUFS_SUPER_MAGIC */
+	if ((statfs(Tcl_GetString (shlibFile), &fs) == 0) &&
+	    (fs.f_type == AUFS_SUPER_MAGIC)) {
+	    return 1;
+	}
+    }
+#endif /* ... NO_FSTATFS */
+#endif /* ... TCL_TEMPLOAD_NO_UNLINK */
+
+    /* Fallback: !hpux, no EV override, no AUFS (detection, nor detected):
+     * Don't skip */
+    return 0;
+#endif /* hpux */
+}
+
 int
 Tcl_LoadFile(
     Tcl_Interp *interp,		/* Used for error reporting. */
@@ -3300,7 +3382,9 @@ Tcl_LoadFile(
      * avoids any worries about leaving the copy laying around on exit.
      */
 
-    if (Tcl_FSDeleteFile(copyToPtr) == TCL_OK) {
+    if (
+	!TclSkipUnlink (copyToPtr) &&
+	(Tcl_FSDeleteFile(copyToPtr) == TCL_OK)) {
 	Tcl_DecrRefCount(copyToPtr);
 
 	/*