Add sk_careful_memcpy to catch undefined behavior in memcpy.

src/core/SkPathRef.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBuffer.h"
 #include "SkOncePtr.h"
 #include "SkPath.h"
@@ skipping 54 matching lines @@
         }
         return;
     }
 
     if (!(*dst)->unique()) {
         dst->reset(new SkPathRef);
     }
 
     if (*dst != &src) {
         (*dst)->resetToSize(src.fVerbCnt, src.fPointCnt, src.fConicWeights.count());
-        memcpy((*dst)->verbsMemWritable(), src.verbsMemBegin(), src.fVerbCnt * sizeof(uint8_t));
+        if (src.verbsMemBegin()) {
+            memcpy((*dst)->verbsMemWritable(), src.verbsMemBegin(), src.fVerbCnt * sizeof(uint8_t));
+        }
         (*dst)->fConicWeights = src.fConicWeights;
     }
 
     SkASSERT((*dst)->countPoints() == src.countPoints());
     SkASSERT((*dst)->countVerbs() == src.countVerbs());
     SkASSERT((*dst)->fConicWeights.count() == src.fConicWeights.count());
 
     // Need to check this here in case (&src == dst)
     bool canXformBounds = !src.fBoundsIsDirty && matrix.rectStaysRect() && src.countPoints() > 1;
 
@@ skipping 182 matching lines @@
                     fConicWeights.bytes() +
                     sizeof(SkRect));
 }
 
 void SkPathRef::copy(const SkPathRef& ref,
                      int additionalReserveVerbs,
                      int additionalReservePoints) {
     SkDEBUGCODE(this->validate();)
     this->resetToSize(ref.fVerbCnt, ref.fPointCnt, ref.fConicWeights.count(),
                         additionalReserveVerbs, additionalReservePoints);
-    memcpy(this->verbsMemWritable(), ref.verbsMemBegin(), ref.fVerbCnt * sizeof(uint8_t));
-    memcpy(this->fPoints, ref.fPoints, ref.fPointCnt * sizeof(SkPoint));
+    if (ref.verbsMemBegin()) {
+        memcpy(this->verbsMemWritable(), ref.verbsMemBegin(), ref.fVerbCnt * sizeof(uint8_t));
+    }
+    if (ref.fPoints) {
+        memcpy(this->fPoints, ref.fPoints, ref.fPointCnt * sizeof(SkPoint));
+    }
     fConicWeights = ref.fConicWeights;
     fBoundsIsDirty = ref.fBoundsIsDirty;
     if (!fBoundsIsDirty) {
         fBounds = ref.fBounds;
         fIsFinite = ref.fIsFinite;
     }
     fSegmentMask = ref.fSegmentMask;
     fIsOval = ref.fIsOval;
     fIsRRect = ref.fIsRRect;
     SkDEBUGCODE(this->validate();)
@@ skipping 349 matching lines @@
                 break;
             default:
                 SkDEBUGFAIL("Unknown Verb");
                 break;
         }
     }
     SkASSERT(mask == fSegmentMask);
 #endif // SK_DEBUG_PATH
 }
 #endif