Qt: fix crash on opening a capture file while loading/saving another

Closing a capture file while it is being loaded will result in a crash.
As a workaround, disallow closing the capture file. The requested action
(e.g. MainWindow::openCaptureFile) will be silently ignored.

While at it, protect process_specified_records (called when saving
files) similarly to cf_read and fix a crash that occurs when a capture
from the Capture Dialog is started while a file is being loaded:

    file.c:360:cf_close: assertion failed: (cf->state != FILE_READ_IN_PROGRESS)

Bug: 10870 # moving rapidly between large files in a file set
Bug: 13594 # start capture while loading/saving file
Bug: 14351 # open another file while loading file
Change-Id: I6ce8f3163c3fa4869f0299e49909a32594326ce4
Reviewed-on: https://code.wireshark.org/review/28541
Petri-Dish: Anders Broman <a.broman58@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 14 insertions, 4 deletions

diff --git a/ui/qt/main_window_slots.cpp b/ui/qt/main_window_slots.cpp
index c209752a89..fd920b488f 100644
--- a/ui/qt/main_window_slots.cpp
+++ b/ui/qt/main_window_slots.cpp
@@ -200,6 +200,10 @@ bool MainWindow::openCaptureFile(QString cf_path, QString read_filter, unsigned
             }
         }
 
+        // TODO detect call from "cf_read" -> "update_progress_dlg"
+        // ("capture_file_.capFile()->read_lock"), possibly queue opening the
+        // file and return early to avoid the warning in testCaptureFileClose.
+
         QString before_what(tr(" before opening another file"));
         if (!testCaptureFileClose(before_what)) {
             ret = false;
@@ -1384,9 +1388,12 @@ void MainWindow::startInterfaceCapture(bool valid, const QString capture_filter)
 {
     capture_filter_valid_ = valid;
     welcome_page_->setCaptureFilter(capture_filter);
-    // The interface tree will update the selected interfaces via its timer
-    // so no need to do anything here.
-    startCapture();
+    QString before_what(tr(" before starting a new capture"));
+    if (testCaptureFileClose(before_what)) {
+        // The interface tree will update the selected interfaces via its timer
+        // so no need to do anything here.
+        startCapture();
+    }
 }
 
 void MainWindow::applyGlobalCommandLineOptions()
@@ -3716,7 +3723,10 @@ void MainWindow::gotoFrame(int packet_num)
 void MainWindow::extcap_options_finished(int result)
 {
     if (result == QDialog::Accepted) {
-        startCapture();
+        QString before_what(tr(" before starting a new capture"));
+        if (testCaptureFileClose(before_what)) {
+            startCapture();
+        }
     }
     this->welcome_page_->getInterfaceFrame()->interfaceListChanged();
 }