Qt: fix use-after-free on error while saving exported packets

When an error occurs while saving packets using the Export Specified
Packets dialog (e.g. try to overwrite the opened capture file), the
dialog is displayed again. As PacketRangeGroupBox freed the packet
selection range, a crash (use-after-free) occurs.

Removes some unnecessary code in MainWindow::exportDissections as well.

Change-Id: I63898427eff7e71799d89c8a22246db8f93a9ff6
Fixes: v2.5.0rc0-968-g38b40acb2d ("Qt: fix a memory leak when exporting packets")
Reviewed-on: https://code.wireshark.org/review/27695
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Tested-by: Petri Dish Buildbot
Reviewed-by: Stig Bjørlykke <stig@bjorlykke.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/file.c b/file.c
index 500a414a0b..c9b46ab7f2 100644
--- a/file.c
+++ b/file.c
@@ -2114,6 +2114,7 @@ cf_retap_packets(capture_file *cf)
                                   "all packets", TRUE, retap_packet,
                                   &callback_args, TRUE);
 
+  packet_range_cleanup(&range);
   epan_dissect_cleanup(&callback_args.edt);
 
   cf_callback_invoke(cf_cb_file_retap_finished, cf);