tree c93db48768c60ebc17f2400ef4594182d37b5406
parent 47477f07ea4fd04b57271e44fa304bd6fd044e07
author Gilad Arnold <garnold@chromium.org> 1431123217 -0700
committer Gilad Arnold <garnold@chromium.org> 1431462208 +0000

update_engine: Delta generator should not read past old image size.

This fixes a problem that was introduced by CL:246670 and caused the
delta generator to fail when generating deltas from a source image
that's smaller than the target image.

The bug is fixed by ensuring that the reading and comparing of unused
blocks is not attempted for block indexes that exceed the size of the
old image. Instead, these blocks are assumed to be new and their content
packaged into the payload.

BUG=chromium:477876
TEST=Unit tests
TEST=delta_generator successfully applied to FSI version 2913.331.0

Change-Id: I10f497954c58b9ab25cbadf4a7d55e48f4e20c2a
Reviewed-on: https://chromium-review.googlesource.com/270388
Tested-by: Gilad Arnold <garnold@chromium.org>
Reviewed-by: Gilad Arnold <garnold@chromium.org>