ui: warn about shortcuts being overwritten for global actions

this is a common mistake, as the code `ActionManager.getInstance().getAction("ActionId").registerCustomShortcutSet(shortcut, component);` will erase user-defined shortcuts from this action.

platform/editor-ui-api/src/com/intellij/openapi/actionSystem/AnAction.java

@@ -16,6 +16,8 @@
 package com.intellij.openapi.actionSystem;
 
 import com.intellij.openapi.Disposable;
+import com.intellij.openapi.application.ApplicationManager;
+import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.project.DumbAware;
 import com.intellij.openapi.project.PossiblyDumbAware;
 import com.intellij.openapi.project.Project;
@@ -63,6 +65,8 @@ import java.util.List;
  * @see com.intellij.openapi.actionSystem.ActionPlaces
  */
 public abstract class AnAction implements PossiblyDumbAware {
+  private static final Logger LOG = Logger.getInstance(AnAction.class);
+
   public static final AnAction[] EMPTY_ARRAY = new AnAction[0];
   @NonNls public static final String ourClientProperty = "AnAction.shortcutSet";
 
@@ -74,6 +78,7 @@ public abstract class AnAction implements PossiblyDumbAware {
   private static final ShortcutSet ourEmptyShortcutSet = new CustomShortcutSet();
   private boolean myIsDefaultIcon = true;
   private boolean myWorksInInjected;
+  private boolean myIsGlobal; // action is registered in ActionManager
 
 
   /**
@@ -149,7 +154,7 @@ public abstract class AnAction implements PossiblyDumbAware {
   }
 
   public final void registerCustomShortcutSet(@NotNull ShortcutSet shortcutSet, @Nullable final JComponent component, @Nullable Disposable parentDisposable) {
-    myShortcutSet = shortcutSet;
+    setShortcutSet(shortcutSet);
     if (component != null){
       @SuppressWarnings("unchecked")
       List<AnAction> actionList = (List<AnAction>)component.getClientProperty(ourClientProperty);
@@ -273,6 +278,9 @@ public abstract class AnAction implements PossiblyDumbAware {
   public abstract void actionPerformed(AnActionEvent e);
 
   protected void setShortcutSet(ShortcutSet shortcutSet) {
+    if (myIsGlobal && myShortcutSet != shortcutSet) {
+      LOG.error("Shortcuts of global AnActions should not be changed outside of KeymapManager");
+    }
     myShortcutSet = shortcutSet;
   }
 
@@ -325,4 +333,8 @@ public abstract class AnAction implements PossiblyDumbAware {
   public String toString() {
     return getTemplatePresentation().toString();
   }
+
+  void markAsGlobal() {
+    myIsGlobal = true;
+  }
 }

platform/platform-api/src/com/intellij/openapi/actionSystem/ActionStub.java

@@ -102,6 +102,7 @@ public class ActionStub extends AnAction{
       targetPresentation.setDescription(sourcePresentation.getDescription());
     }
     targetAction.setShortcutSet(getShortcutSet());
+    targetAction.markAsGlobal();
   }
 
   public String getProjectType() {