Add Ctrl+Q and ask before quitting with an unsaved upscale

Quit and window close share closeEvent, so both ask. The unsaved check
moves into discard_ok, used by Clear as well.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

3 files changed, 37 insertions, 4 deletions

diff --git a/README.md b/README.md
index cd73c5e..71ae4a0 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,7 @@ Small PyQt6 app to upscale an image with an ESRGAN model through `sd-cli` (stabl
 - Save As (Ctrl+Shift+S) writes a new file. Overwrite replaces the original after a confirmation, in the same format. EXIF metadata is not kept.
 - Clear (Ctrl+W) empties the view and deletes the temp files. It asks first if the upscaled image was not saved.
 - Settings holds the upscalers folder.
+- Ctrl+Q quits. Quitting or closing the window asks first if the upscaled image was not saved.
 
 ### Model descriptions
 
diff --git a/test_upscale_qt.py b/test_upscale_qt.py
index 66423e8..7175e92 100644
--- a/test_upscale_qt.py
+++ b/test_upscale_qt.py
@@ -114,6 +114,25 @@ def test_main_window():
     assert not w.a_clear.isEnabled() and not w.a_up.isEnabled()
 
 
+def test_quit_asks_when_unsaved():
+    from PyQt6.QtWidgets import QMessageBox
+    w = uq.Main()
+    assert w.a_quit.shortcut().toString() == 'Ctrl+Q'
+    path = os.path.join(TMP, 'q.png')
+    QImage(4, 4, QImage.Format.Format_RGB32).save(path)
+    w.load(path)
+    w.jobs[0].result = QImage(16, 16, QImage.Format.Format_RGB32)
+    answers = []
+    real = QMessageBox.question
+    try:
+        QMessageBox.question = lambda *a: answers.append(a) or QMessageBox.StandardButton.No
+        assert not w.close() and len(answers) == 1      # declined, stays open
+        w.jobs[0].saved = True
+        assert w.close() and len(answers) == 1          # saved, no question
+    finally:
+        QMessageBox.question = real
+
+
 if __name__ == '__main__':
     for name, fn in list(globals().items()):
         if name.startswith('test_'):
diff --git a/upscale-qt b/upscale-qt
index 5f22a5c..3515a1b 100755
--- a/upscale-qt
+++ b/upscale-qt
@@ -249,6 +249,10 @@ class Main(QMainWindow):
         self.a_over = act('Overwrite', 'document-save', self.overwrite)
         self.a_clear = act('Clear', 'edit-clear', self.clear, 'Ctrl+W')
         act('Settings', 'preferences-system', self.settings)
+        self.a_quit = QAction('Quit', self)   # window-wide, not on the toolbar
+        self.a_quit.setShortcut(QKeySequence.StandardKey.Quit)
+        self.a_quit.triggered.connect(self.close)
+        self.addAction(self.a_quit)
 
         self.proc = QProcess(self)
         self.proc.finished.connect(self.proc_done)
@@ -394,12 +398,18 @@ class Main(QMainWindow):
         else:
             QMessageBox.warning(self, 'upscale-qt', f'Cannot write {job.path}, original untouched')
 
-    def clear(self):
+    def discard_ok(self, title):
+        """True unless an unsaved upscale exists and the user keeps it."""
         job = self.job()
-        if job.result is not None and not job.saved and QMessageBox.question(
-                self, 'Clear', 'The upscaled image is not saved. Discard it?'
-                ) != QMessageBox.StandardButton.Yes:
+        return (job is None or job.result is None or job.saved
+                or QMessageBox.question(
+                    self, title, 'The upscaled image is not saved. Discard it?'
+                ) == QMessageBox.StandardButton.Yes)
+
+    def clear(self):
+        if not self.discard_ok('Clear'):
             return
+        job = self.job()
         for f in (job.input, job.out):
             if f and os.path.exists(f):
                 os.remove(f)   # 4x PNGs run to hundreds of MB
@@ -414,6 +424,9 @@ class Main(QMainWindow):
             self.reload_models()
 
     def closeEvent(self, e):
+        if not self.discard_ok('Quit'):
+            e.ignore()
+            return
         if self.proc.state() != QProcess.ProcessState.NotRunning:
             self.proc.kill()
             self.proc.waitForFinished(2000)