Provide a friendlier error message after Rietveld issue deletion.

Provide a friendlier error message after Rietveld issue deletion.

As a n0oB to Chrome, I sometimes deleted uploaded CLs on codereview.chromium.org
after looking at them and deciding they were unsuitable for review. I
would then later git cl upload and get a confusing stacktrace about a
404. This change lets the user know why the error happened, and how to
resolve it.

I decided not to auto-scrub the old issue on the client side, because
the 404 might be spurious (server misconfiguration, bug in my code, etc.).
Safer to make the user explicitly run the command.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=116360

[M-A Ruel, 2012-01-04 17:56:48]

http://codereview.chromium.org/9091009/diff/2001/git_cl.py
File git_cl.py (right):

http://codereview.chromium.org/9091009/diff/2001/git_cl.py#newcode518
git_cl.py:518: except urllib2.HTTPError, e:
I'd prefer to have this at line 448 so all calls would be properly handled.

[miket_OOO, 2012-01-04 19:12:29]

> I'd prefer to have this at line 448 so all calls would be properly handled.

Good point. Done. Also reformatted the message a little to fit an 80-column
screen.

[M-A Ruel, 2012-01-04 19:16:35]

http://codereview.chromium.org/9091009/diff/2002/git_cl.py
File git_cl.py (right):

http://codereview.chromium.org/9091009/diff/2002/git_cl.py#newcode456
git_cl.py:456: '404 (not found)\nerror. It is likely that you deleted this '
I prefer to have each \n to end the string even if it looks a bit clunky in the
sources. e.g.
('\nWhile fetching the description for issue %d, received a '
 '404 (not found)\n'
 'error. It is likely that you deleted this issue on the '
 'server. If this is the\n'
 'case, please run\n\n'
...

http://codereview.chromium.org/9091009/diff/2002/git_cl.py#newcode462
git_cl.py:462: DieWithError('\nFailed to fetch issue description. HTTP error ' +
I prefer this alignment:

DieWithError(
    '\nFailed to fetch issue description. HTTP error %s' % e.code)

[miket_OOO, 2012-01-04 19:35:12]

Reformatted.

[M-A Ruel, 2012-01-04 19:38:32]

lgtm

[commit-bot: I haz the power, 2012-01-04 19:38:41]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/miket@chromium.org/9091009/8001

[commit-bot: I haz the power, 2012-01-04 19:44:59]

Change committed as 116360