@@ -1144,7 +1144,7 @@ private void handleSketchProblems(PreprocessedSketch ps) {
     static private JavaProblem convertIProblem(IProblem iproblem, PreprocessedSketch ps) {
       SketchInterval in = ps.mapJavaToSketch(iproblem);
       if (in == SketchInterval.BEFORE_START) return null;
-      String badCode = ps.pdeCode.substring(in.startPdeOffset, in.stopPdeOffset);
+      String badCode = ps.getPdeCode(in);
       int line = ps.tabOffsetToTabLine(in.tabIndex, in.startTabOffset);
       JavaProblem p = JavaProblem.fromIProblem(iproblem, in.tabIndex, line, badCode);
       p.setPDEOffsets(in.startTabOffset, in.stopTabOffset);
@@ -1213,7 +1213,7 @@ static private List<JavaProblem> checkForCurlyQuotes(PreprocessedSketch ps) {
           case IProblem.UnterminatedString:
             SketchInterval in = ps.mapJavaToSketch(iproblem);
             if (in == SketchInterval.BEFORE_START) continue;
-            String badCode = ps.pdeCode.substring(in.startPdeOffset, in.stopPdeOffset);
+            String badCode = ps.getPdeCode(in);
             matcher.reset(badCode);
             while (matcher.find()) {
               int offset = matcher.start();
 
@@ -77,6 +77,14 @@ public boolean inRange(SketchInterval interval) {
   }
 
 
+  public String getPdeCode(SketchInterval si) {
+    if (si == SketchInterval.BEFORE_START) return "";
+    int stop = Math.min(si.stopPdeOffset, pdeCode.length());
+    int start = Math.min(si.startPdeOffset, stop);
+    return pdeCode.substring(start, stop);
+  }
+
+
   public SketchInterval mapJavaToSketch(ASTNode node) {
     return mapJavaToSketch(node.getStartPosition(),
                            node.getStartPosition() + node.getLength());