Qt: fix hang on exiting Qt while loading capture file

testCaptureFileClose can also be invoked while reading an existing
capture file (the original comment only applied to GTK+, not Qt). When
the user quits Wireshark while reading an offline pcap, this could
result in a confusing "Unsaved packets" dialog. Fix this by checking the
actual capture session state.

After fixing this, the next issue is that cf_close trips on an assertion
("cf->state != FILE_READ_IN_PROGRESS"). To address this problem, do not
close the capture file immediately, but signal to the reader (cf_read)
that this should be done (similar to the quit logic in GTK+).

Bug: 13563
Change-Id: I12d4b813557bf354199320df2ed8609070fdc58a
Reviewed-on: https://code.wireshark.org/review/22096
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
(cherry picked from commit 800a856fb4784e31347e15a8ec825d2daeb62350)
Reviewed-on: https://code.wireshark.org/review/22190

1 files changed, 18 insertions, 0 deletions

diff --git a/file.c b/file.c
index 7cbab798ee..dab712685c 100644
--- a/file.c
+++ b/file.c
@@ -541,6 +541,7 @@ cf_read(capture_file *cf, gboolean reloading)
   volatile gboolean    create_proto_tree;
   guint                tap_flags;
   gboolean             compiled;
+  volatile gboolean    is_read_aborted = FALSE;
 
   /* Compile the current display filter.
    * We assume this will not fail since cf->dfilter is only set in
@@ -642,6 +643,13 @@ cf_read(capture_file *cf, gboolean reloading)
         }
       }
 
+      if (cf->state == FILE_READ_ABORTED) {
+        /* Well, the user decided to exit Wireshark.  Break out of the
+           loop, and let the code below (which is called even if there
+           aren't any packets left to read) exit. */
+        is_read_aborted = TRUE;
+        break;
+      }
       if (cf->stop_flag) {
         /* Well, the user decided to abort the read. He/She will be warned and
            it might be enough for him/her to work with the already loaded
@@ -717,6 +725,16 @@ cf_read(capture_file *cf, gboolean reloading)
     packet_list_select_first_row();
   }
 
+  if (is_read_aborted) {
+    /*
+     * Well, the user decided to exit Wireshark while reading this *offline*
+     * capture file (Live captures are handled by something like
+     * cf_continue_tail). Clean up accordingly.
+     */
+    cf_close(cf);
+    return CF_READ_ABORTED;
+  }
+
   if (cf->stop_flag) {
     simple_message_box(ESD_TYPE_WARN, NULL,
                   "The remaining packets in the file were discarded.\n"