Fix bug9931 'Encapsulated ethernet packets sometimes show invalid FCS'

This fixes part-1 of bug9931: the uninitialized use of a wtap_pkthdr
struct. The second part of the bug deals with dissectors calling
the Ethernet dissector for ecnapsulated Ethernet packets but using
the wrong dissector handle to do so. That's unrelated to the issue this
commit addresses, so I'm splitting them up.

Change-Id: I87be7b736f82dd74d8c261062f88143372b5344c
Reviewed-on: https://code.wireshark.org/review/848
Reviewed-by: Hadriel Kaplan <hadrielk@yahoo.com>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/file.c b/file.c
index a37a0524ab..95d2bd23dc 100644
--- a/file.c
+++ b/file.c
@@ -4019,7 +4019,7 @@ cf_get_comment(capture_file *cf, const frame_data *fd)
     struct wtap_pkthdr phdr; /* Packet header */
     Buffer buf; /* Packet data */
 
-    phdr.opt_comment = NULL;
+    memset(&phdr, 0, sizeof(struct wtap_pkthdr));
 
     buffer_init(&buf, 1500);
     if (!cf_read_frame_r(cf, fd, &phdr, &buf))