mailinfo: avoid segfault when can't open files

If <msg> or <patch> files can't be opened, then mailinfo() returns an
error before it even initializes mi->p_hdr_data or mi->s_hdr_data.
When cmd_mailinfo() then calls clear_mailinfo(), we dereference the
NULL pointers trying to free their contents.

Signed-off-by: Juan F. Codagnone <jcodagnone@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/mailinfo.c b/mailinfo.c
index a489d9d0fbcc37a1198247a8daae4b3104ebe284..36ec927b9ef9e41c08ba5934b450980002b98aca 100644 (file)
--- a/mailinfo.c
+++ b/mailinfo.c
@@ -1149,11 +1149,13 @@ void clear_mailinfo(struct mailinfo *mi)
        strbuf_release(&mi->inbody_header_accum);
        free(mi->message_id);
 
-       for (i = 0; mi->p_hdr_data[i]; i++)
-               strbuf_release(mi->p_hdr_data[i]);
+       if (mi->p_hdr_data)
+               for (i = 0; mi->p_hdr_data[i]; i++)
+                       strbuf_release(mi->p_hdr_data[i]);
        free(mi->p_hdr_data);
-       for (i = 0; mi->s_hdr_data[i]; i++)
-               strbuf_release(mi->s_hdr_data[i]);
+       if (mi->s_hdr_data)
+               for (i = 0; mi->s_hdr_data[i]; i++)
+                       strbuf_release(mi->s_hdr_data[i]);
        free(mi->s_hdr_data);
 
        while (mi->content < mi->content_top) {