Fix repository dropdown corruption bugs (#1912, #1915)

- Remove line in init_repo_stats() that deleted "No repository selected"
  from dropdown, which caused index shifting and corruption
- Fix repo_unlink_action() to disconnect signals before manipulating
  the dropdown to prevent cascading updates
- Fix flaky test_repo_unlink by using direct function call and waitSignal()

Author: m3nu

src/vorta/views/repo_tab.py

@@ -146,9 +146,6 @@ def init_repo_stats(self):
         # set labels
         repo: RepoModel = self.profile().repo
         if repo is not None:
-            # remove *unset* item
-            self.repoSelector.removeItem(self.repoSelector.findData(None))
-
             # Start with every element enabled, then disable SSH-related if relevant
             for child in self.frameRepoSettings.children():
                 child.setEnabled(True)
@@ -309,11 +306,6 @@ def process_new_repo(self, result):
 
     def repo_unlink_action(self):
         profile = self.profile()
-        self.init_repo_stats()
-
-        msg = QMessageBox()
-        msg.setStandardButtons(QMessageBox.StandardButton.Ok)
-        msg.setParent(self, QtCore.Qt.WindowType.Sheet)
 
         selected_repo_id = self.repoSelector.currentData()
         selected_repo_index = self.repoSelector.currentIndex()
@@ -322,15 +314,26 @@ def repo_unlink_action(self):
             # QComboBox is empty / repo unset
             return
 
+        # Disconnect signal before manipulating dropdown to prevent cascading updates
+        try:
+            self.repoSelector.currentIndexChanged.disconnect(self.repo_select_action)
+        except TypeError:
+            pass
+
+        # Update database
         repo = RepoModel.get(id=selected_repo_id)
         ArchiveModel.delete().where(ArchiveModel.repo_id == repo.id).execute()
         profile.repo = None
         profile.save()
-
         repo.delete_instance(recursive=True)  # This also deletes archives.
-        self.repoSelector.setCurrentIndex(0)
+
+        # Update dropdown
         self.repoSelector.removeItem(selected_repo_index)
+        self.repoSelector.setCurrentIndex(0)
 
+        msg = QMessageBox()
+        msg.setStandardButtons(QMessageBox.StandardButton.Ok)
+        msg.setParent(self, QtCore.Qt.WindowType.Sheet)
         msg.setWindowTitle(self.tr('Repository was Unlinked'))
         msg.setText(self.tr('You can always connect it again later.'))
         msg.show()

tests/unit/test_repo.py

@@ -71,9 +71,10 @@ def test_repo_unlink(qapp, qtbot, monkeypatch):
     qtbot.waitUntil(lambda: tab.repoSelector.count() == 1, **pytest._wait_defaults)
     assert RepoModel.select().count() == 0
 
-    qtbot.mouseClick(main.createStartBtn, QtCore.Qt.MouseButton.LeftButton)
-    # -1 is the repo id in this test
-    qtbot.waitUntil(lambda: 'Select a backup repository first.' in main.progressText.text(), **pytest._wait_defaults)
+    # Directly call create_backup_action and wait for signal
+    with qtbot.waitSignal(qapp.backup_progress_event, timeout=5000):
+        qapp.create_backup_action()
+
     assert 'Select a backup repository first.' in main.progressText.text()