gpg: close stderr once finished with it in verify_signed_buffer()

Failing to close the stderr pipe in verify_signed_buffer() causes
git to run out of file descriptors if there are many calls to
verify_signed_buffer(). An easy way to trigger this is to run

 git log --show-signature --merges | grep "key"

on the linux kernel git repo. Eventually it will fail with

 error: cannot create pipe for gpg: Too many open files
 error: could not run gpg.

Close the stderr pipe so that this can't happen.

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/gpg-interface.c b/gpg-interface.c
index ff232c8c5d47f42481e3de365442e46967432022..bcf55a433e53a0ffc351316c505eb3585b8fb47f 100644 (file)
--- a/gpg-interface.c
+++ b/gpg-interface.c
@@ -128,8 +128,10 @@ int verify_signed_buffer(const char *payload, size_t payload_size,
        write_in_full(gpg.in, payload, payload_size);
        close(gpg.in);
 
-       if (gpg_output)
+       if (gpg_output) {
                strbuf_read(gpg_output, gpg.err, 0);
+               close(gpg.err);
+       }
        ret = finish_command(&gpg);
 
        unlink_or_warn(path);