tree 56f40ca47fd3b1398a0f691c2697a78afc86fe51
parent 975e86643939308559293ee1562a654cf874f259
author Jae Hoon Kim <kimjae@chromium.org> 1590027979 -0700
committer Commit Bot <commit-bot@chromium.org> 1590094461 +0000

update_engine: Fix ubsan error for undefined-behavior

The error:
   "runtime error: applying non-zero offset 224 to null pointer"

Incrementing past the |std::vector<T>::end()| is undefined behavior,
hence we must check before assigning the |second| variable based off of
|first| because |first| may be |std::vector<T>::end()|.

BUG=chromium:1067975
TEST=USE="${USE} ubsan" FEATURES=test P2_TEST_FILTER=*EmptyFilesystemTest*-*RunAsRoot* emerge-$B update_engine

Change-Id: I9fb2a213464755c4cf115dc5ba3e658a927d0262
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/2210979
Tested-by: Jae Hoon Kim <kimjae@chromium.org>
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Commit-Queue: Jae Hoon Kim <kimjae@chromium.org>