When converting JDT AST to IR, a do-while loop in a case statement will throw NPE (#186)

* Fixed bug for source analysis

Do while in case statement would throw an NPE. Now it doesn't

* Added test case

The test will fail with an NPE if the fix is not applied.

com.ibm.wala.cast.java.ecj/src/com/ibm/wala/cast/java/translator/jdt/JDTJava2CAstTranslator.java

@@ -2444,7 +2444,9 @@ public abstract class JDTJava2CAstTranslator<T extends Position> {
     WalkContext loopContext = new LoopContext(context, loopLabel, breakTarget, continueTarget);
     CAstNode loopBody = visitNode(n.getBody(), loopContext);
 
-    return doLoopTranslator.translateDoLoop(loopTest, loopBody, continueNode, breakNode, context);  
+    CAstNode madeNode = doLoopTranslator.translateDoLoop(loopTest, loopBody, continueNode, breakNode, context);
+    context.pos().setPosition(madeNode, makePosition(n));
+    return madeNode;
   }
 
   /**

com.ibm.wala.cast.java.test.data/src/bugfixes/DoWhileInCase.java

@@ -0,0 +1,17 @@
+package bugfixes;
+
+public class DoWhileInCase {
+  static int x = 3;
+  public static void main(String[] args) {
+    switch(x) {
+    case 1:
+      do {
+        System.out.println("Problem");
+        x ++;
+      } while (x < 3);
+      break;
+    default:
+      System.out.println("Default");
+    }
+  }
+}

com.ibm.wala.cast.java.test/src/com/ibm/wala/cast/java/test/JavaIRTests.java

@@ -630,5 +630,9 @@ public abstract class JavaIRTests extends IRTests {
     Assert.assertEquals(2, SlicerTest.countAllocations(slice));
     Assert.assertEquals(2, SlicerTest.countPutfields(slice));
   }
+  
+  @Test public void testDoWhileInCase() throws IllegalArgumentException, CancelException, IOException {
+    runTest(singleTestSrc("bugfixes"), rtJar, simplePkgTestEntryPoint("bugfixes"), emptyList, true); 
+  }
 
 }