Merge "Add comment explaining why we need custom logic to parse int" am: be81a990b3 am: 94af5fff58 am: 30ed9f9151
Original change: https://android-review.googlesource.com/c/platform/external/bsdiff/+/1680665
Change-Id: If7f10430533b6386582c7a96d9076b79aee762d2
diff --git a/utils.cc b/utils.cc
index c3e613e..c82eb98 100644
--- a/utils.cc
+++ b/utils.cc
@@ -7,6 +7,11 @@
namespace bsdiff {
int64_t ParseInt64(const uint8_t* buf) {
+ // BSPatch uses a non-standard encoding of integers.
+ // Highest bit of that integer is used as a sign bit, 1 = negative
+ // and 0 = positive.
+ // Therefore, if the highest bit is set, flip it, then do 2's complement
+ // to get the integer in standard form
int64_t result = buf[7] & 0x7F;
for (int i = 6; i >= 0; i--) {
result <<= 8;
