Fix overflow when comparing two ints by promoting the sum to 64-bits.
R=reed@google.com, scroggo@google.com
Author: djsollen@google.com
Review URL: https://codereview.chromium.org/505153003
diff --git a/src/images/SkImageDecoder_libico.cpp b/src/images/SkImageDecoder_libico.cpp
index 90058d6..f75d804 100644
--- a/src/images/SkImageDecoder_libico.cpp
+++ b/src/images/SkImageDecoder_libico.cpp
@@ -154,7 +154,8 @@
//int fakeBitCount = read2Bytes(buf, 12 + choice*16); //should be real - usually 0
const size_t size = read4Bytes(buf, 14 + choice*16); //matters?
const size_t offset = read4Bytes(buf, 18 + choice*16);
- if ((offset + size) > length) {
+ // promote the sum to 64-bits to avoid overflow
+ if (((uint64_t)offset + size) > length) {
return false;
}