Prevent signal recursion when canceling group change

Use explicit disconnect/connect of the signal handler when resetting
combobox text to prevent recursion in selectedGroupChanged.

Author: wyu71

src/lib/configwidgetslib/impage.cpp

@@ -201,12 +201,22 @@ void IMPage::selectedGroupChanged() {
         return;
     }
     if (!config_->currentGroup().isEmpty() && config_->needSave()) {
-        if (QMessageBox::No ==
-            QMessageBox::question(this, _("Current group changed"),
-                                  _("Do you want to change group? Changes to "
-                                    "current group will be lost!"))) {
-            ui_->inputMethodGroupComboBox->setCurrentText(
-                config_->currentGroup());
+        if (QMessageBox::No == QMessageBox::question(
+                this, _("Current group changed"),
+                _("Do you want to change group? Changes to current group will be "
+                  "lost!"))) {
+            // Temporarily disconnect our signal handler
+            QMetaObject::Connection connection =
+                disconnect(ui_->inputMethodGroupComboBox,
+                          &QComboBox::currentTextChanged, this,
+                          &IMPage::selectedGroupChanged);
+            ui_->inputMethodGroupComboBox->setCurrentText(config_->currentGroup());
+            // Restore our signal handler
+            if (connection) {
+                connect(ui_->inputMethodGroupComboBox,
+                       &QComboBox::currentTextChanged, this,
+                       &IMPage::selectedGroupChanged);
+            }
             return;
         }
     }