Fix updating the state of menus.

The menus were only updated during context changes
(not if action states where updated directly),
and didn't take into account that the active action for a context
might still be disabled.
Also, enabled separators should not automatically lead to enabled menus.

src/plugins/coreplugin/actionmanager/command.cpp

@@ -337,11 +337,17 @@ bool Shortcut::setCurrentContext(const QList<int> &context)
 {
     foreach (int ctxt, m_context) {
         if (context.contains(ctxt)) {
-            m_shortcut->setEnabled(true);
+            if (!m_shortcut->isEnabled()) {
+                m_shortcut->setEnabled(true);
+                emit activeStateChanged();
+            }
             return true;
         }
     }
-    m_shortcut->setEnabled(false);
+    if (m_shortcut->isEnabled()) {
+        m_shortcut->setEnabled(false);
+        emit activeStateChanged();
+    }
     return false;
 }
 
@@ -454,14 +460,13 @@ bool Action::setCurrentContext(const QList<int> &context)
         // we need to update the checked state, so we connect to setChecked slot, which also fires a toggled signal
         connect(m_action, SIGNAL(toggled(bool)), m_currentAction, SLOT(setChecked(bool)));
         actionChanged();
-        m_active = true;
         return true;
     }
     // no active/delegate action, "visible" action is not enabled/visible
     if (hasAttribute(CA_Hide))
         m_action->setVisible(false);
     m_action->setEnabled(false);
-    m_active = false;
+    setActive(false);
     return false;
 }
 
@@ -517,9 +522,18 @@ void Action::actionChanged()
 
     m_action->setEnabled(m_currentAction->isEnabled());
     m_action->setVisible(m_currentAction->isVisible());
+    setActive(m_action->isEnabled() && m_action->isVisible() && !m_action->isSeparator());
 }
 
 bool Action::isActive() const
 {
     return m_active;
 }
+
+void Action::setActive(bool state)
+{
+    if (state != m_active) {
+        m_active = state;
+        emit activeStateChanged();
+    }
+}