Take cygwin handling of X11 into account

Implement TclpIsAtty, Cygwin only
doc/dde.n: doc fix

3 files changed, 18 insertions, 4 deletions

diff --git a/generic/tclInt.decls b/generic/tclInt.decls
index 9eb8320..97517ea 100644
--- a/generic/tclInt.decls
+++ b/generic/tclInt.decls
@@ -1084,6 +1084,10 @@ declare 15 win {
 	    const char **argv, TclFile inputFile, TclFile outputFile,
 	    TclFile errorFile, Tcl_Pid *pidPtr)
 }
+# new for 8.4.20+/8.5.12+ Cygwin only
+declare 16 win {
+    int TclpIsAtty(int fd)
+}
 # Signature changed in 8.1:
 #  declare 16 win {
 #      TclFile TclpCreateTempFile(char *contents, Tcl_DString *namePtr)
diff --git a/generic/tclIntPlatDecls.h b/generic/tclIntPlatDecls.h
index 77cf197..960a4f2 100644
--- a/generic/tclIntPlatDecls.h
+++ b/generic/tclIntPlatDecls.h
@@ -138,7 +138,8 @@ EXTERN int		TclpCreateProcess(Tcl_Interp *interp, int argc,
 				const char **argv, TclFile inputFile,
 				TclFile outputFile, TclFile errorFile,
 				Tcl_Pid *pidPtr);
-/* Slot 16 is reserved */
+/* 16 */
+EXTERN int		TclpIsAtty(int fd);
 /* Slot 17 is reserved */
 /* 18 */
 EXTERN TclFile		TclpMakeFile(Tcl_Channel channel, int direction);
@@ -287,7 +288,7 @@ typedef struct TclIntPlatStubs {
     Tcl_Channel (*tclpCreateCommandChannel) (TclFile readFile, TclFile writeFile, TclFile errorFile, int numPids, Tcl_Pid *pidPtr); /* 13 */
     int (*tclpCreatePipe) (TclFile *readPipe, TclFile *writePipe); /* 14 */
     int (*tclpCreateProcess) (Tcl_Interp *interp, int argc, const char **argv, TclFile inputFile, TclFile outputFile, TclFile errorFile, Tcl_Pid *pidPtr); /* 15 */
-    void (*reserved16)(void);
+    int (*tclpIsAtty) (int fd); /* 16 */
     void (*reserved17)(void);
     TclFile (*tclpMakeFile) (Tcl_Channel channel, int direction); /* 18 */
     TclFile (*tclpOpenFile) (const char *fname, int mode); /* 19 */
@@ -430,7 +431,8 @@ extern const TclIntPlatStubs *tclIntPlatStubsPtr;
 	(tclIntPlatStubsPtr->tclpCreatePipe) /* 14 */
 #define TclpCreateProcess \
 	(tclIntPlatStubsPtr->tclpCreateProcess) /* 15 */
-/* Slot 16 is reserved */
+#define TclpIsAtty \
+	(tclIntPlatStubsPtr->tclpIsAtty) /* 16 */
 /* Slot 17 is reserved */
 #define TclpMakeFile \
 	(tclIntPlatStubsPtr->tclpMakeFile) /* 18 */
diff --git a/generic/tclStubInit.c b/generic/tclStubInit.c
index 0f0665b..1cbcf84 100644
--- a/generic/tclStubInit.c
+++ b/generic/tclStubInit.c
@@ -56,7 +56,9 @@ static int TclSockMinimumBuffersOld(int sock, int size)
 #ifdef __WIN32__
 #   define TclUnixWaitForFile 0
 #   define TclpReaddir 0
+#   define TclpIsAtty 0
 #elif defined(__CYGWIN__)
+#   define TclpIsAtty TclPlatIsAtty
 #   define TclWinSetInterfaces (void (*) (int)) doNothing
 #   define TclWinAddProcess (void (*) (void *, unsigned int)) doNothing
 #   define TclWinFlushDirtyChannels doNothing
@@ -64,6 +66,12 @@ static int TclSockMinimumBuffersOld(int sock, int size)
 
 static Tcl_Encoding winTCharEncoding;
 
+static int
+TclpIsAtty(int fd)
+{
+    return isatty(fd);
+}
+
 int
 TclWinGetPlatformId()
 {
@@ -489,7 +497,7 @@ static const TclIntPlatStubs tclIntPlatStubs = {
     TclpCreateCommandChannel, /* 13 */
     TclpCreatePipe, /* 14 */
     TclpCreateProcess, /* 15 */
-    0, /* 16 */
+    TclpIsAtty, /* 16 */
     0, /* 17 */
     TclpMakeFile, /* 18 */
     TclpOpenFile, /* 19 */