IDEA-167841 IncorrectOperationException on for -> foreach

plugins/InspectionGadgets/src/com/siyeh/ig/migration/ForCanBeForeachInspection.java

@@ -809,6 +809,11 @@ public class ForCanBeForeachInspection extends ForCanBeForeachInspectionBase {
   private static String getVariableReferenceText(PsiReferenceExpression reference, PsiVariable variable, PsiElement context) {
     final String text = reference.getText();
     final PsiResolveHelper resolveHelper = PsiResolveHelper.SERVICE.getInstance(context.getProject());
+    PsiExpression qualifier = reference.getQualifierExpression();
+    while(qualifier != null) {
+      if(!(qualifier instanceof PsiReferenceExpression)) return text;
+      qualifier = ((PsiReferenceExpression)qualifier).getQualifierExpression();
+    }
     final PsiVariable target = resolveHelper.resolveReferencedVariable(text, context);
     return variable != target ? ExpressionUtils.getQualifierOrThis(reference).getText() + "." + text : text;
   }

plugins/InspectionGadgets/test/com/siyeh/igfixes/migration/for_can_be_foreach/ForQualifiedArray.after.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2000-2017 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.
+ */
+
+// "Replace with 'foreach'" "true"
+import java.util.*;
+
+public class Test {
+  private String[] fields = null;
+
+  void test() {
+      for (String field : this.fields) {
+      }
+  }

plugins/InspectionGadgets/test/com/siyeh/igfixes/migration/for_can_be_foreach/ForQualifiedArray.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2000-2017 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.
+ */
+
+// "Replace with 'foreach'" "true"
+import java.util.*;
+
+public class Test {
+  private String[] fields = null;
+
+  void test() {
+    fo<caret>r (int i = 0; i < this.fields.length; i++) {
+      String field = fields[i];
+
+    }
+  }

plugins/InspectionGadgets/testsrc/com/siyeh/ig/fixes/migration/ForCanBeForeachFixTest.java

@@ -30,6 +30,7 @@ public class ForCanBeForeachFixTest extends IGQuickFixesTestCase {
   public void testForThisClass() { doTest(); }
   public void testForOuterClass() { doTest(); }
   public void testForOuterClassIterator() { doTest(); }
+  public void testForQualifiedArray() { doTest(); }
 
   @Override
   public void setUp() throws Exception {