Qt: fix crashes when Wireshark is closed while running a capture

if we haven't captured any packets yet, don't display a warning about
unsaved changes

make sure that we're not running into a scenario where
MainWindow::testCaptureFileClose() tries to close the capture file at
the same time as the pipe handler who sees an eof on the pipe

cf_has_unsaved_data() should return false if we have a temporary file
that contains no packets

Change-Id: I18d75bd658b85d45dd3313d49e2cd654c6300de5
Reviewed-on: https://code.wireshark.org/review/9109
Reviewed-by: Evan Huus <eapache@gmail.com>
Petri-Dish: Anders Broman <a.broman58@gmail.com>
Petri-Dish: Gerald Combs <gerald@wireshark.org>
Petri-Dish: Martin Kaiser <wireshark@kaiser.cx>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/file.c b/file.c
index 4755394963..39f500448c 100644
--- a/file.c
+++ b/file.c
@@ -4336,7 +4336,7 @@ cf_has_unsaved_data(capture_file *cf)
    * If this is a temporary file, or a file with unsaved changes, it
    * has unsaved data.
    */
-  return cf->is_tempfile || cf->unsaved_changes;
+  return (cf->is_tempfile && cf->count>0) || cf->unsaved_changes;
 }
 
 /*