Use spawnl() rather than pipe() & fork() to invoke xkbcomp

Implement System() specially on Cygwin not to use fork() and exec(), but
spawnl()

Use System() and a temp file rather than pipe() & fork() to invoke xkbcomp on
cygwin, just as done on mingw

Somewhat the counsel of despair, but sometimes Windows is being such a little
bitch that the cygwin DLL just can't emulate fork() successfully, so just using
spawnl() here is more robust and means I don't have to deal with end-users
reporting this as a problem with the xserver

Popen is not used, but must be built as it is referenced by sdksyms

v2: Update to include fix to Win32TempDir() when TMP is set but TEMP isn't

XXX: Really this should check TMPDIR first, as that's the canonical UNIX way to
set the temporary directory?

v3: Fix implicit-function-declaration of Win32TempDir() in XkbDDXCompileKeymapByNames()

Add a prototype for Win32TempDir()

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>

1 files changed, 32 insertions, 0 deletions

diff --git a/os/utils.c b/os/utils.c
index 04642f703..0a3aa572d 100644
--- a/os/utils.c
+++ b/os/utils.c
@@ -1337,6 +1337,26 @@ OsAbort(void)
  * as well.  As it is now, xkbcomp messages don't end up in the log file.
  */
 
+#ifdef __CYGWIN__
+#include <process.h>
+int
+System(const char *command)
+{
+    int status;
+
+    if (!command)
+        return 1;
+
+    DebugF("System: `%s'\n", command);
+
+    /*
+       Use spawnl() rather than execl() to implement System() on cygwin to
+       avoid fork emulation overhead and brittleness
+     */
+    status = spawnl(_P_WAIT, "/bin/sh", "sh", "-c", command, (char *) NULL);
+    return status;
+}
+#else
 int
 System(const char *command)
 {
@@ -1378,6 +1398,7 @@ System(const char *command)
 
     return p == -1 ? -1 : status;
 }
+#endif
 
 static struct pid {
     struct pid *next;
@@ -1689,6 +1710,17 @@ System(const char *cmdline)
 
     return dwExitCode;
 }
+#elif defined(__CYGWIN__)
+const char*
+Win32TempDir(void)
+{
+    if (getenv("TEMP") != NULL)
+        return getenv("TEMP");
+    else if (getenv("TMP") != NULL)
+        return getenv("TMP");
+    else
+        return "/tmp";
+}
 #endif
 
 /*