Gerrit git cl: allow overriding GERRIT_SQUASH_UPLOADS in git config.

Gerrit git cl: allow overriding GERRIT_SQUASH_UPLOADS in git config.

Previously, if GERRIT_SQUASH_UPLOADS was found in codereview.settings,
a local repository value of gerrit.squash-uploads would be set.

This CL changes that, so that gerrit.squash-uploads property is written
with GERRIT_SQUASH_UPLOADS value ONLY IF the property wasn't set before.

This allows individual users to choose their own way with
  git config [--global] -bool gerrit.squash-uploads (true|false)

BUG=611892
R=andybons@chromium.org,sergiyb@chromium.org

Committed: https://chromium.googlesource.com/chromium/tools/depot_tools/+/768ec9a75560b5e5903d86654d4c1ab2afe17361

[Sergiy Byelozyorov, 2016-06-15 15:40:46]

lgtm w/ suggestion

https://codereview.chromium.org/2070013002/diff/1/git_cl.py
File git_cl.py (right):

https://codereview.chromium.org/2070013002/diff/1/git_cl.py#newcode2840
git_cl.py:2840: # Do not override existing setting, if any.
imho this comment is confusing, inside if we actually do override existing
setting because no existing one was set. I suggest moving it to the previous
line and changing like this:

if not cur:  # Set the value only if it wasn't set by the user manually.

[tandrii(chromium), 2016-06-15 15:42:05]

The CQ bit was checked by tandrii@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-06-15 15:42:14]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2070013002/20001

[commit-bot: I haz the power, 2016-06-15 15:49:21]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-06-15 15:49:22]

Dry run: Try jobs failed on following builders:
  Depot Tools Presubmit on tryserver.infra (JOB_FAILED,
https://build.chromium.org/p/tryserver.infra/builders/Depot%20Tools%20Presubm...)

[tandrii(chromium), 2016-06-16 14:36:12]

The CQ bit was checked by tandrii@chromium.org

[tandrii(chromium), 2016-06-16 14:36:12]

The patchset sent to the CQ was uploaded after l-g-t-m from sergiyb@chromium.org
Link to the patchset: https://codereview.chromium.org/2070013002/#ps20001
(title: "review")

[commit-bot: I haz the power, 2016-06-16 14:36:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2070013002/20001

[commit-bot: I haz the power, 2016-06-16 14:39:14]

Description was changed from

==========
Gerrit git cl: allow overriding GERRIT_SQUASH_UPLOADS in git config.

Previously, if GERRIT_SQUASH_UPLOADS was found in codereview.settings,
a local repository value of gerrit.squash-uploads would be set.

This CL changes that, so that gerrit.squash-uploads property is written
with GERRIT_SQUASH_UPLOADS value ONLY IF the property wasn't set before.

This allows individual users to choose their own way with
  git config [--global] -bool gerrit.squash-uploads (true|false)

BUG=611892
R=andybons@chromium.org,sergiyb@chromium.org
==========

to

==========
Gerrit git cl: allow overriding GERRIT_SQUASH_UPLOADS in git config.

Previously, if GERRIT_SQUASH_UPLOADS was found in codereview.settings,
a local repository value of gerrit.squash-uploads would be set.

This CL changes that, so that gerrit.squash-uploads property is written
with GERRIT_SQUASH_UPLOADS value ONLY IF the property wasn't set before.

This allows individual users to choose their own way with
  git config [--global] -bool gerrit.squash-uploads (true|false)

BUG=611892
R=andybons@chromium.org,sergiyb@chromium.org

Committed:
https://chromium.googlesource.com/chromium/tools/depot_tools/+/768ec9a75560b5...
==========

[commit-bot: I haz the power, 2016-06-16 14:39:15]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/tools/depot_tools/+/768ec9a75560b5...

[tandrii(chromium), 2016-06-16 20:24:06]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/2071963002/ by tandrii@chromium.org.

The reason for reverting is: I suspect this broke squash setting setup..