call getClasses() in read action (EA-64639 - assert: PsiFileImpl.getStubTree)

plugins/coverage/src/com/intellij/coverage/view/JavaCoverageViewExtension.java

@@ -1,3 +1,18 @@
+/*
+ * Copyright 2000-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package com.intellij.coverage.view;
 
 import com.intellij.coverage.*;
@@ -235,9 +250,13 @@ public class JavaCoverageViewExtension extends CoverageViewExtension {
                      : PsiFile.EMPTY_ARRAY;
             }
           });
-          for (PsiFile file : childFiles) {
+          for (final PsiFile file : childFiles) {
             if (file instanceof PsiJavaFile) {
-              PsiClass[] classes = ((PsiJavaFile)file).getClasses();
+              PsiClass[] classes = ApplicationManager.getApplication().runReadAction(new Computable<PsiClass[]>() {
+                public PsiClass[] compute() {
+                  return ((PsiJavaFile) file).getClasses();
+                }
+              });
               if (classes.length > 0) {
                 PsiClass aClass = classes[0];
                 if (!(node instanceof CoverageListRootNode) && getClassCoverageInfo(aClass) == null) continue;