execv_dashed_external: stop exiting with negative code

When we try to exec a git sub-command, we pass along the
status code from run_command(). But that may return -1 if we
ran into an error with pipe() or execve(). This tends to
work (and end up as 255 due to twos-complement wraparound
and truncation), but in general it's probably a good idea to
avoid negative exit codes for portability.

We can easily translate to the normal generic "128" code we
get when syscalls cause us to die.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git.c b/git.c
index d0e04d5c97bd6497cdea97110873e8c8e65bcb64..bc2f2a7ec9dd3fe1bc92ab9d5f1e52987fe7f899 100644 (file)
--- a/git.c
+++ b/git.c
@@ -593,12 +593,16 @@ static void execv_dashed_external(const char **argv)
        trace_argv_printf(cmd.args.argv, "trace: exec:");
 
        /*
-        * if we fail because the command is not found, it is
-        * OK to return. Otherwise, we just pass along the status code.
+        * If we fail because the command is not found, it is
+        * OK to return. Otherwise, we just pass along the status code,
+        * or our usual generic code if we were not even able to exec
+        * the program.
         */
        status = run_command(&cmd);
-       if (status >= 0 || errno != ENOENT)
+       if (status >= 0)
                exit(status);
+       else if (errno != ENOENT)
+               exit(128);
 }
 
 static int run_argv(int *argcp, const char ***argv)