This makes now the same simplification as the chromium
release scripts do. For creating branch B from a gnumbd'ed
(aka real) commit X do:
1. Branch Y off the real X
2. Set refs/pending/heads/B to Y
3. Set refs/pending-tags/B to X
4. Set refs/heads/B to X
The old algorithm tried to branch off the pending
correspondent of X. That commit was determined by comparing
tree objects of the real X and commits on pending.
Unfortunately, multiple commits on one branch can refer to
the same tree object, e.g., for commits P, Q, R with R being
the revert of Q, P and R refer to the same tree object.
TBR=tandrii@chromium.org
NOTRY=true
TEST=./script_test.py
TEST=tools/release/create_release.py -a me -r you --dry-run
Review URL: https://codereview.chromium.org/979243004
Cr-Commit-Position: refs/heads/master@{#27042}
This is needed as normal chromium checkouts don't fetch
branch-heads.
These branches will also be replicated by GitHub and are
fetched when cloning from the repository.
The expected object size will be the same or smaller than
before as we currently push the same information onto the
candidates branch (which already is in refs/heads). The only
difference is the increasing number of refs in refs/heads.
BUG=chromium:451975
TBR=tandrii@chromium.org
NOTRY=true
LOG=n
TEST=./script_test.py
TEST=tools/release/create_release.py -r machenbach@chromium.org -a machenbach@chromium.org --dry-run
Review URL: https://codereview.chromium.org/914973002
Cr-Commit-Position: refs/heads/master@{#26629}
