fix wtf crash when deps entry is at None

fix wtf crash when deps entry is at None

There are several places where we advise people
to use custom_deps with { "foo" : None } to avoid
checking out certain sub-repos.  This caused wtf to
crash on startup.


BUG=


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=156373

[M-A Ruel, 2012-09-12 20:34:14]

lgtm anyhow even with slow code.

http://codereview.chromium.org/10917220/diff/1/wtf
File wtf (right):

http://codereview.chromium.org/10917220/diff/1/wtf#newcode67
wtf:67: raw = [k for k, v in entries.items() if v and not re.search('svn', v)]
raw = sorted(k for k, v in entries.itermitems() if v and not re.search('svn',
v))

would be sooo much faster. At least an order of magnitude. :)

[sbc, 2012-09-12 20:49:21]

Out of interest, is it iteritems() or sorted() that you think would make such
a bug difference?    I guess each one avoids an entire copy of the
entries.. anything
else?

On Wed, Sep 12, 2012 at 1:34 PM,  <maruel@chromium.org> wrote:
> lgtm anyhow even with slow code.
>
>
> http://codereview.chromium.org/10917220/diff/1/wtf
> File wtf (right):
>
> http://codereview.chromium.org/10917220/diff/1/wtf#newcode67
> wtf:67: raw = [k for k, v in entries.items() if v and not
> re.search('svn', v)]
> raw = sorted(k for k, v in entries.itermitems() if v and not
> re.search('svn', v))
>
> would be sooo much faster. At least an order of magnitude. :)
>
> http://codereview.chromium.org/10917220/

[M-A Ruel, 2012-09-12 20:55:40]

On 2012/09/12 20:49:21, sbc_google.com wrote:
> Out of interest, is it iteritems() or sorted() that you think would make such
> a bug difference?    I guess each one avoids an entire copy of the
> entries.. anything
> else?

iteritems() removes the need of a copy.
sorted() without constructing a list removes the need to instantiate the
unsorted list at all, it is created sorted as the generator executes.

Really no big deal.

[Sam Clegg, 2012-09-12 20:56:56]

On 2012/09/12 20:55:40, Marc-Antoine Ruel wrote:
> On 2012/09/12 20:49:21, http://sbc_google.com wrote:
> > Out of interest, is it iteritems() or sorted() that you think would make
such
> > a bug difference?    I guess each one avoids an entire copy of the
> > entries.. anything
> > else?
> 
> iteritems() removes the need of a copy.
> sorted() without constructing a list removes the need to instantiate the
> unsorted list at all, it is created sorted as the generator executes.
> 
> Really no big deal.

Can I use the commit box in code review to commit this, or does
somebody need to commit for me?

[commit-bot: I haz the power, 2012-09-12 20:59:56]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/sbc@chromium.org/10917220/1

[commit-bot: I haz the power, 2012-09-12 21:02:03]

Change committed as 156373