Bug 374471 Make the noautohide attribute live where supported r=enndeakin

layout/xul/nsMenuPopupFrame.cpp

@@ -2101,6 +2101,14 @@ nsMenuPopupFrame::AttributeChanged(int32_t aNameSpaceID,
   if (aAttribute == nsGkAtoms::left || aAttribute == nsGkAtoms::top)
     MoveToAttributePosition();
 
+#ifndef MOZ_GTK2
+  if (aAttribute == nsGkAtoms::noautohide) {
+    nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
+    if (pm)
+      pm->EnableRollup(mContent, !IsNoAutoHide());
+  }
+#endif
+
   if (aAttribute == nsGkAtoms::label) {
     // set the label for the titlebar
     nsView* view = GetView();

layout/xul/nsXULPopupManager.cpp

@@ -1236,6 +1236,41 @@ nsXULPopupManager::HidePopupsInList(const nsTArray<nsMenuPopupFrame *> &aFrames)
   SetCaptureState(nullptr);
 }
 
+void
+nsXULPopupManager::EnableRollup(nsIContent* aPopup, bool aShouldRollup)
+{
+#ifndef MOZ_GTK
+  if (aShouldRollup) {
+    nsMenuChainItem* item = mNoHidePanels;
+    while (item) {
+      if (item->Content() == aPopup) {
+        item->Detach(&mNoHidePanels);
+        nsIContent* oldmenu = nullptr;
+        if (mPopups)
+          oldmenu = mPopups->Content();
+        item->SetParent(mPopups);
+        mPopups = item;
+        SetCaptureState(oldmenu);
+        return;
+      }
+      item = item->GetParent();
+    }
+  } else {
+    nsMenuChainItem* item = mPopups;
+    while (item) {
+      if (item->Content() == aPopup) {
+        item->Detach(&mPopups);
+        item->SetParent(mNoHidePanels);
+        mNoHidePanels = item;
+        SetCaptureState(nullptr);
+        return;
+      }
+      item = item->GetParent();
+    }
+  }
+#endif
+}
+
 bool
 nsXULPopupManager::IsChildOfDocShell(nsIDocument* aDoc, nsIDocShellTreeItem* aExpected)
 {

layout/xul/nsXULPopupManager.h

@@ -484,6 +484,14 @@ public:
    */
   void HidePopupsInDocShell(nsIDocShellTreeItem* aDocShellToHide);
 
+  /**
+   * Enable or disable the dynamic noautohide state of a panel.
+   *
+   * aPanel - the panel whose state is to change
+   * aShouldRollup - whether the panel is no longer noautohide
+   */
+  void EnableRollup(nsIContent* aPopup, bool aShouldRollup);
+
   /**
    * Execute a menu command from the triggering event aEvent.
    *