pub: treat a pubspec with just comments as empty

pub: treat a pubspec with just comments as empty

BUG= http://dartbug.com/3483

TEST=

Committed: https://code.google.com/p/dart/source/detail?r=9686

[kevmoo-old, 2012-06-09 21:42:01]

Tiny tweak, but nice if folks have comment-only pubspecs.

For instance, they are using library boiler-plate with placeholder

[kevmoo-old, 2012-06-12 03:41:12]

Not sure if I already did this...

[kevmoo-old, 2012-07-14 21:47:16]

Bob told me to bother you w/ this.

[nweiz, 2012-07-16 19:34:02]

Could you also add a test for this to pubspec_test?

http://codereview.chromium.org/10534081/diff/1/utils/pub/pubspec.dart
File utils/pub/pubspec.dart (right):

http://codereview.chromium.org/10534081/diff/1/utils/pub/pubspec.dart#newcode45
utils/pub/pubspec.dart:45: if (parsedPubspec == null) {
Nit: we usually do single-line if statements when they're just returning a value
(as above).

[nweiz, 2012-07-16 22:41:04]

LGTM, I'll go ahead and commit this.