notice null colorfilter in legacy unflattening

src/effects/SkColorFilterImageFilter.cpp

 /*
  * Copyright 2012 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 "SkColorFilterImageFilter.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
@@ skipping 67 matching lines @@
     }
     return SkNEW_ARGS(SkColorFilterImageFilter, (cf, input, cropRect, uniqueID));
 }
 
 SkColorFilterImageFilter::SkColorFilterImageFilter(SkColorFilter* cf,
         SkImageFilter* input, const CropRect* cropRect, uint32_t uniqueID)
     : INHERITED(1, &input, cropRect, uniqueID), fColorFilter(SkRef(cf)) {
 }
 
 #ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
-SkColorFilterImageFilter::SkColorFilterImageFilter(SkReadBuffer& buffer)
-  : INHERITED(1, buffer) {
+SkColorFilterImageFilter::SkColorFilterImageFilter(SkReadBuffer& buffer) : INHERITED(1, buffer) {
     fColorFilter = buffer.readColorFilter();
+    // we aren't prepared for this to be NULL, and it can't ever be when we're NOT supporting
+    // SK_SUPPORT_LEGACY_DEEPFLATTENING, as we always go through a factory which can detect
+    // NULL. However, since here we're in the legacy code, we assign a dummy filter so we
+    // don't crash with a null-ptr.
+    if (NULL == fColorFilter) {
+        // colormatrix identity is effectively a no-op
+        fColorFilter = SkColorMatrixFilter::Create(SkColorMatrix());
+        SkASSERT(fColorFilter);
+    }
 }
 #endif
 
 SkFlattenable* SkColorFilterImageFilter::CreateProc(SkReadBuffer& buffer) {
     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
     SkAutoTUnref<SkColorFilter> cf(buffer.readColorFilter());
     return Create(cf, common.getInput(0), &common.cropRect(), common.uniqueID());
 }
 
 void SkColorFilterImageFilter::flatten(SkWriteBuffer& buffer) const {
@@ skipping 40 matching lines @@
 bool SkColorFilterImageFilter::asColorFilter(SkColorFilter** filter) const {
     if (!cropRectIsSet()) {
         if (filter) {
             *filter = fColorFilter;
             fColorFilter->ref();
         }
         return true;
     }
     return false;
 }