Adding error checks to SkRBuffer

src/core/SkValidatingReadBuffer.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 "SkBitmap.h"
 #include "SkErrorInternals.h"
 #include "SkValidatingReadBuffer.h"
 #include "SkStream.h"
 #include "SkTypeface.h"
 
 SkValidatingReadBuffer::SkValidatingReadBuffer(const void* data, size_t size) :
     fError(false) {
     this->setMemory(data, size);
     this->setFlags(SkFlattenableReadBuffer::kValidation_Flag);
 }
 
 SkValidatingReadBuffer::~SkValidatingReadBuffer() {
 }
 
-void SkValidatingReadBuffer::validate(bool isValid) {
+bool SkValidatingReadBuffer::validate(bool isValid) {
     if (!fError && !isValid) {
         // When an error is found, send the read cursor to the end of the stream
         fReader.skip(fReader.available());
         fError = true;
     }
+    return !fError;
 }
 
 void SkValidatingReadBuffer::setMemory(const void* data, size_t size) {
     this->validate(IsPtrAlign4(data) && (SkAlign4(size) == size));
     if (!fError) {
         fReader.setMemory(data, size);
     }
 }
 
 const void* SkValidatingReadBuffer::skip(size_t size) {
@@ skipping 75 matching lines @@
 
 void SkValidatingReadBuffer::readPoint(SkPoint* point) {
     point->fX = fReader.readScalar();
     point->fY = fReader.readScalar();
 }
 
 void SkValidatingReadBuffer::readMatrix(SkMatrix* matrix) {
     size_t size = 0;
     if (!fError) {
         size = matrix->readFromMemory(fReader.peek(), fReader.available());
-        this->validate((SkAlign4(size) != size) || (0 == size));
+        this->validate((SkAlign4(size) == size) && (0 != size));
     }
     if (!fError) {
         (void)this->skip(size);
     }
 }
 
 void SkValidatingReadBuffer::readIRect(SkIRect* rect) {
     const void* ptr = this->skip(sizeof(SkIRect));
     if (!fError) {
         memcpy(rect, ptr, sizeof(SkIRect));
     }
 }
 
 void SkValidatingReadBuffer::readRect(SkRect* rect) {
     const void* ptr = this->skip(sizeof(SkRect));
     if (!fError) {
         memcpy(rect, ptr, sizeof(SkRect));
     }
 }
 
 void SkValidatingReadBuffer::readRegion(SkRegion* region) {
     size_t size = 0;
     if (!fError) {
         size = region->readFromMemory(fReader.peek(), fReader.available());
-        this->validate((SkAlign4(size) != size) || (0 == size));
+        this->validate((SkAlign4(size) == size) && (0 != size));
     }
     if (!fError) {
         (void)this->skip(size);
     }
 }
 
 void SkValidatingReadBuffer::readPath(SkPath* path) {
     size_t size = 0;
     if (!fError) {
         size = path->readFromMemory(fReader.peek(), fReader.available());
-        this->validate((SkAlign4(size) != size) || (0 == size));
+        this->validate((SkAlign4(size) == size) && (0 != size));
     }
     if (!fError) {
         (void)this->skip(size);
     }
 }
 
 bool SkValidatingReadBuffer::readArray(void* value, size_t size, size_t elementSize) {
     const uint32_t count = this->getArrayCount();
     this->validate(size == count);
     (void)this->skip(sizeof(uint32_t)); // Skip array count
@@ skipping 84 matching lines @@
             delete obj;
             obj = NULL;
         }
     } else {
         // we must skip the remaining data
         this->skip(sizeRecorded);
         SkASSERT(false);
     }
     return obj;
 }