VCS: Clear commit message hint when editor becomes disabled

The commit editor becomes disabled, when no more
changed files were available. In this case, the
commit message verification makes no sense and
should be removed.

Change-Id: Ic16cc4ade1ecd1b64faee52b21a10b9c882908d0
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/vcsbase/submiteditorwidget.cpp

@@ -435,6 +435,12 @@ void SubmitEditorWidget::updateSubmitAction()
     }
 }
 
+void SubmitEditorWidget::changeEvent(QEvent *event)
+{
+    if (event->type() == QEvent::EnabledChange)
+        verifyDescription();
+}
+
 // Enable diff depending on selected files
 void SubmitEditorWidget::updateDiffAction()
 {
@@ -506,6 +512,12 @@ void SubmitEditorWidget::hideDescription()
 
 void SubmitEditorWidget::verifyDescription()
 {
+    if (!isEnabled()) {
+        d->m_ui.descriptionHint->setText(QString());
+        d->m_ui.descriptionHint->setToolTip(QString());
+        return;
+    }
+
     auto fontColor = [](Utils::Theme::Color color) {
         return QString("<font color=\"%1\">")
                 .arg(Utils::creatorTheme()->color(color).name());

src/plugins/vcsbase/submiteditorwidget.h

@@ -111,6 +111,7 @@ signals:
     void submitActionEnabledChanged(bool);
 
 protected:
+    virtual void changeEvent(QEvent *event) override;
     virtual QString cleanupDescription(const QString &) const;
     virtual QString commitName() const;
     void insertTopWidget(QWidget *w);