ui: do not leak disposed Content via layout after toolwindow deactivation

Disposed Content was accessible via myLastLayout.toDrop collection.

GitOrigin-RevId: 8dcc2647e374c46848cbfa50b2c92951defc32ef

platform/platform-impl/src/com/intellij/openapi/wm/impl/ToolWindowImpl.kt

@@ -8,7 +8,6 @@ import com.intellij.ide.actions.*
 import com.intellij.ide.impl.ContentManagerWatcher
 import com.intellij.idea.ActionsBundle
 import com.intellij.internal.statistic.eventLog.EventPair
-import com.intellij.internal.statistic.eventLog.FeatureUsageData
 import com.intellij.notification.EventLog
 import com.intellij.openapi.Disposable
 import com.intellij.openapi.actionSystem.*
@@ -321,6 +320,10 @@ internal class ToolWindowImpl(val toolWindowManager: ToolWindowManagerImpl,
     if (isAvailable != value) {
       isAvailable = value
       toolWindowManager.toolWindowPropertyChanged(this, ToolWindowProperty.AVAILABLE)
+
+      if (!value) {
+        contentUi?.dropCaches()
+      }
     }
   }
 

platform/platform-impl/src/com/intellij/openapi/wm/impl/content/TabContentLayout.java

@@ -87,6 +87,10 @@ final class TabContentLayout extends ContentLayout implements MorePopupAware {
     return myLastLayout.moreRect;
   }
 
+  public void dropCaches() {
+    myLastLayout = null;
+  }
+
   @Override
   public boolean canShowMorePopup() {
     return getMoreRect() != null;

platform/platform-impl/src/com/intellij/openapi/wm/impl/content/ToolWindowContentUi.java

@@ -225,6 +225,10 @@ public final class ToolWindowContentUi implements ContentUI, DataProvider {
     contentComponent.repaint();
   }
 
+  public void dropCaches() {
+    tabsLayout.dropCaches();
+  }
+
   private void rebuild() {
     getCurrentLayout().rebuild();
     getCurrentLayout().update();