Add check for bad dash interval in dash effect picture read

src/effects/SkDashPathEffect.cpp

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkDashPathEffect.h"
@@ skipping 547 matching lines @@
     size_t allocSize = sizeof(SkScalar) * fCount;
     if (buffer.validateAvailable(allocSize)) {
         fIntervals = (SkScalar*)sk_malloc_throw(allocSize);
         buffer.readScalarArray(fIntervals, fCount);
     } else {
         fIntervals = NULL;
     }
 
     if (useOldPic) {
         fPhase = 0;
-        for (int i = 0; i < fInitialDashIndex; ++i) {
-            fPhase += fIntervals[i];
+        if (fInitialDashLength != -1) { // Signal for bad dash interval
+            for (int i = 0; i < fInitialDashIndex; ++i) {
+                fPhase += fIntervals[i];
+            }
+            fPhase += fIntervals[fInitialDashIndex] - fInitialDashLength;
         }
-        fPhase += fIntervals[fInitialDashIndex] - fInitialDashLength;
     } else {
         this->setInternalMembers(fPhase);
     }
 }