Checking structure sizes before reading them from memory to avoid overflowing the buffer's stream.

include/core/SkWriter32.h

Index: include/core/SkWriter32.h
diff --git a/include/core/SkWriter32.h b/include/core/SkWriter32.h
index ba8893eab960244f7418612fc9666f2a0bf97f4b..5882d16e20aefb58c821474e01a2a9559f77977a 100644
--- a/include/core/SkWriter32.h
+++ b/include/core/SkWriter32.h
@@ -129,9 +129,17 @@ public:
     }
 
     void writeMatrix(const SkMatrix& matrix) {
-        size_t size = matrix.writeToMemory(NULL);
-        SkASSERT(SkAlign4(size) == size);
-        matrix.writeToMemory(this->reserve(size));
+        for (int i = 0; i < 9; ++i) {
+            this->writeScalar(matrix[i]);

[mtklein, 2013/10/25 18:11:49]

Were we just never writing the flags at all?

[sugoi1, 2013/10/25 18:27:20]

No, SkMatrix::writeToMemory() was only writing the SkScalar values.

+        }
+    }
+
+    uint32_t writeMatrixSize(const SkMatrix&) const {
+        return 9 * sizeof(SkScalar);
+    }
+
+    static uint32_t MaxWriteMatrixSize() {
+        return 9 * sizeof(SkScalar) + sizeof(uint32_t);
     }
 
     void writeRegion(const SkRegion& rgn) {