Fix bug #18745 with invoking Windows batch files with embedded whitespace.

 src/w32proc.c (create_child): If calling a quoted batch file,
 pass NULL for exe.

 nt/cmdproxy.c (batch_file_p): New function.
 (spawn): If calling a quoted batch file pass NULL for progname.

 test/automated/process-tests.el (process-test-quoted-batfile): New test.

2 files changed, 15 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index a1b70b63755..fb724fb583f 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2014-10-25  Noam Postavsky  <npostavs@users.sourceforget.net>
+
+        * src/w32proc.c (create_child): If calling a quoted batch file,
+        pass NULL for exe.  (Bug#18745)
+
 2014-10-24  Eli Zaretskii  <eliz@gnu.org>
 
         * bidi.c (bidi_resolve_explicit, bidi_find_bracket_pairs)
diff --git a/src/w32proc.c b/src/w32proc.c
index 38452917add..09e0c0530a4 100644
--- a/src/w32proc.c
+++ b/src/w32proc.c
@@ -1078,6 +1078,7 @@ create_child (char *exe, char *cmdline, char *env, int is_gui_app,
   DWORD flags;
   char dir[ MAX_PATH ];
   char *p;
+  const char *ext;
 
   if (cp == NULL) emacs_abort ();
 
@@ -1116,6 +1117,15 @@ create_child (char *exe, char *cmdline, char *env, int is_gui_app,
     if (*p == '/')
       *p = '\\';
 
+  /* CreateProcess handles batch files as exe specially.  This special
+     handling fails when both the batch file and arguments are quoted.
+     We pass NULL as exe to avoid the special handling. */
+  if (exe && cmdline[0] == '"' &&
+      (ext = strrchr (exe, '.')) &&
+      (xstrcasecmp (ext, ".bat") == 0
+       || xstrcasecmp (ext, ".cmd") == 0))
+      exe = NULL;
+
   flags = (!NILP (Vw32_start_process_share_console)
            ? CREATE_NEW_PROCESS_GROUP
            : CREATE_NEW_CONSOLE);