* sysdep.c (sys_subshell): Use 'volatile' to avoid vfork clobbering.

Before, this 'volatile' was incorrectly IF_LINTted out.

diff --git a/src/ChangeLog b/src/ChangeLog
index da9676233e06877eb91bf1d0fc0dbd06daed185b..53f66bd80323a6651f2933fc6a5d65789b68882b 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,8 @@
 2011-03-18  Paul Eggert  <eggert@cs.ucla.edu>
 
+       * sysdep.c (sys_subshell): Use 'volatile' to avoid vfork clobbering.
+       Before, this 'volatile' was incorrectly IF_LINTted out.
+
        * lisp.h (child_setup): Now NO_RETURN unless DOS_NT.
        This should get cleaned up, so that child_setup has the
        same signature on all platforms.

diff --git a/src/sysdep.c b/src/sysdep.c
index 6ef3d88c5c8917357a1ea8791723a677fb254b95..889ff6d83ebf257811eeac8f4607528912c0e6d0 100644 (file)
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -488,7 +488,11 @@ sys_subshell (void)
   int pid;
   struct save_signal saved_handlers[5];
   Lisp_Object dir;
-  unsigned char * IF_LINT (volatile) str = 0;
+
+  /* Volatile because otherwise vfork might clobber it on some hosts.  */
+  unsigned char *volatile dirstr = 0;
+
+  unsigned char *str;
   int len;
 
   saved_handlers[0].code = SIGINT;
@@ -512,7 +516,7 @@ sys_subshell (void)
     goto xyzzy;
 
   dir = expand_and_dir_to_file (Funhandled_file_name_directory (dir), Qnil);
-  str = (unsigned char *) alloca (SCHARS (dir) + 2);
+  str = dirstr = (unsigned char *) alloca (SCHARS (dir) + 2);
   len = SCHARS (dir);
   memcpy (str, SDATA (dir), len);
   if (str[len - 1] != '/') str[len++] = '/';
@@ -544,6 +548,7 @@ sys_subshell (void)
        sh = "sh";
 
       /* Use our buffer's default directory for the subshell.  */
+      str = dirstr;
       if (str && chdir ((char *) str) != 0)
        {
 #ifndef DOS_NT