IG: ignore blocks containing error elements (IDEA-177570)

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/style/SingleStatementInBlockInspection.java

@@ -21,6 +21,7 @@ import com.intellij.openapi.util.Pair;
 import com.intellij.psi.*;
 import com.intellij.psi.util.FileTypeUtils;
 import com.intellij.psi.util.PsiUtil;
+import com.intellij.psi.util.PsiUtilCore;
 import com.siyeh.InspectionGadgetsBundle;
 import com.siyeh.ig.BaseInspection;
 import com.siyeh.ig.BaseInspectionVisitor;
@@ -97,7 +98,11 @@ public class SingleStatementInBlockInspection extends BaseInspection {
     @Override
     protected boolean isApplicable(PsiStatement body) {
       if (body instanceof PsiBlockStatement) {
-        final PsiStatement[] statements = ((PsiBlockStatement)body).getCodeBlock().getStatements();
+        final PsiCodeBlock codeBlock = ((PsiBlockStatement)body).getCodeBlock();
+        if (PsiUtilCore.hasErrorElementChild(codeBlock)) {
+          return false;
+        }
+        final PsiStatement[] statements = codeBlock.getStatements();
         if (statements.length == 1 && !(statements[0] instanceof PsiDeclarationStatement) && !isDanglingElseProblem(statements[0], body)) {
           final PsiFile file = body.getContainingFile();
           //this inspection doesn't work in JSP files, as it can't tell about tags

plugins/InspectionGadgets/test/com/siyeh/igfixes/single_statement_block/ForMalformed.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.
+ */
+class X {
+  public int toIntegerValue() {
+    int result = 0;
+    fo<caret>r (CssPrefix prefix : myEnabledPrefixes) {
+      float (getValue) {
+        result |= prefix.myIntMask;
+      }
+    }
+    return result;
+  }
+  
+  void anotherMethod() {}
+}

plugins/InspectionGadgets/testsrc/com/siyeh/ig/fixes/braces/SingleStatementInBlockFixTest.java

@@ -33,6 +33,7 @@ public class SingleStatementInBlockFixTest extends IGQuickFixesTestCase {
   public void testWhile() { doTest("while"); }
   public void testForEach() { doTest("for"); }
   public void testForIndex() { doTest("for"); }
+  public void testForMalformed() { assertQuickfixNotAvailable(getMessage("for"));}
   public void testDoWhile() { doTest("do"); }
   public void testIfWithLoop() { doTest("if"); }
   public void testElseWithLoop() { doTest("else"); }