1203686 - Add git support to mach try's "find files changed in the current branch" feature

Status: RESOLVED FIXED

(Testing :: General, defect)

Description

[Chris Manchester (limited bugmail, email directly)]

There's a plausible approach thanks to :jgraham based on git branch -a --contains and git ref-list, but according to http://marc.info/?l=git&m=143218896817198&w=2 and other threads on the list both of these commands are likely to fail on repositories like mozilla-central, where subsequent commits frequently have non-increasing commit dates.

There are probably a few more ideas that might work, we can discuss here.

Comment 1

[Chris Manchester (limited bugmail, email directly)]

My current idea is:

Get all branches with git branch -a.
For each branch that isn't the current branch, find git merge-base HEAD $branch.
Run git log --topo-order and iterate over the results in order and find the first commit that's also a merge-base.
Run git diff --name-only with this commit.

It's very slow, but I can't think of a way it would break.

Comment 2

[Mike Hommey [:glandium]]

git merge-base HEAD $(git branch -a) might actually work to find the right base commit for the diff

Comment 3

[Mike Hommey [:glandium]]

(with the asterisk removed from git branch -a)

Comment 4

[Mike Hommey [:glandium]]

Err, another shortcoming of git branch -a: it shows symbolic refs like "remotes/origin/HEAD -> origin/master"

Comment 5

[Chris Manchester (limited bugmail, email directly)]

Thanks glandium, I didn't notice merge-base works with more than two commits. Filtering the output of for-each-ref should work instead of git branch -a.

Comment 6

[Chris Manchester (limited bugmail, email directly)]

Attachment: MozReview Request: Bug 1203686 - Add git support to mach try's ability to find files changes on the current branch. r=jgraham

Bug 1203686 - Add git support to mach try's ability to find files changes on the current branch. r=jgraham

Comment 7

[James Graham [:jgraham]]

Comment on attachment 8668573 [details]
MozReview Request: Bug 1203686 - Add git support to mach try's ability to find files changes on the current branch. r=jgraham

https://reviewboard.mozilla.org/r/20983/#review18869

::: testing/tools/autotry/autotry.py:339
(Diff revision 1)
> +            args = ['git', 'diff', '--name-only', 'HEAD', base_commit]

Probably better to do this with -z and split on null.

::: testing/tools/autotry/autotry.py:418
(Diff revision 1)
>          hg_args = [

For consistency I would mildly prefer if we had both git and hg implementations in their own method and this method.

::: testing/tools/autotry/autotry.py:427
(Diff revision 1)
>          return subprocess.check_output(hg_args).splitlines()

Shouldn't this have some friendly error message if it fails?

Comment 8

[Chris Manchester (limited bugmail, email directly)]

https://reviewboard.mozilla.org/r/20983/#review18869

> Shouldn't this have some friendly error message if it fails?

If a single invocation of hg log fails, I would think the cause would be obvious, but sure.

Comment 9

[Chris Manchester (limited bugmail, email directly)]

Comment on attachment 8668573 [details]
MozReview Request: Bug 1203686 - Add git support to mach try's ability to find files changes on the current branch. r=jgraham

Bug 1203686 - Add git support to mach try's ability to find files changes on the current branch. r=jgraham

Comment 10

[James Graham [:jgraham]]

Comment on attachment 8668573 [details]
MozReview Request: Bug 1203686 - Add git support to mach try's ability to find files changes on the current branch. r=jgraham

https://reviewboard.mozilla.org/r/20983/#review18887

Comment 11

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/4aa419a04237

Comment 12

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/4aa419a04237