safe_create_leading_directories_const(): preserve errno

Some implementations of free() change errno (even thought they
shouldn't):

  https://sourceware.org/bugzilla/show_bug.cgi?id=17924

So preserve the errno from safe_create_leading_directories() across the
call to free().

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/sha1_file.c b/sha1_file.c
index 1173071859dae68f72cc72efb20f816152d3eabc..10395e7e4bb53e107bfb26bdc84768d0883d362f 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -166,10 +166,14 @@ enum scld_error safe_create_leading_directories(char *path)
 
 enum scld_error safe_create_leading_directories_const(const char *path)
 {
+       int save_errno;
        /* path points to cache entries, so xstrdup before messing with it */
        char *buf = xstrdup(path);
        enum scld_error result = safe_create_leading_directories(buf);
+
+       save_errno = errno;
        free(buf);
+       errno = save_errno;
        return result;
 }