git: Try a bit harder not to lose errno in stdio

This switches the checks around upon the exit codepath of the
git wrapper, so that we may recover at least non-transient errors.

It's still not perfect. As I've been harping on, stdio simply isn't very
good for error reporting. For example, if an IO error happened, you'd want
to see EIO, wouldn't you? And yes, that's what the kernel would return.
However, with buffered stdio (and flushing outside of our control), what
would likely happen is that some intermediate error return _does_ return
EIO, but then the kernel might decide to re-mount the filesystem read-only
due to the error, and the actual *report* for us might be

	"write failure on standard output: read-only filesystem"

which lost the EIO.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git.c b/git.c
index c65e52f3db908f30fba85b9b57e5a72aebd45c3f..cfec5d70ee42852f3819fe46e99ebc70f089ccc7 100644 (file)
--- a/git.c
+++ b/git.c
@@ -251,11 +251,12 @@ static int run_command(struct cmd_struct *p, int argc, const char **argv)
                return 0;
 
        /* Check for ENOSPC and EIO errors.. */
-       if (ferror(stdout))
-               die("write failure on standard output");
-       if (fflush(stdout) || fclose(stdout))
+       if (fflush(stdout))
                die("write failure on standard output: %s", strerror(errno));
-
+       if (ferror(stdout))
+               die("unknown write failure on standard output");
+       if (fclose(stdout))
+               die("close failed on standard output: %s", strerror(errno));
        return 0;
 }