update_engine: Merge contiguous operations (reprise).
This is reapplying CL:269604 with a small fix that prevents it from
adding spurious src_length fields when merging payload operations. This
also revises relevant unit tests to catch the said error. The original
change is described below.
Merges operations of type SOURCE_COPY, REPLACE, or REPLACE_BZ if they
have the same type, are contiguous, have only one destination extent,
and their combined block count does not exceed the chunk size.
BUG=chromium:461651
BUG=chromium:486497
TEST=Unit test (fails before fix, passes after)
TEST=Trybot
Change-Id: I9f3d7f653454e27177428f2d7c0e6485184a7f8b
Reviewed-on: https://chromium-review.googlesource.com/270268
Trybot-Ready: Gilad Arnold <garnold@chromium.org>
Tested-by: Gilad Arnold <garnold@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Commit-Queue: Gilad Arnold <garnold@chromium.org>
10 files changed