When translating from file to URI, make sure translation is reversible.

When translating from file to URI, make sure translation is reversible.

BUG=dartbug.com/22555
R=brianwilkerson@google.com

Committed: https://code.google.com/p/dart/source/detail?r=44003

[Paul Berry, 2015-02-24 21:58:16]

paulberry@google.com changed reviewers:
+ brianwilkerson@google.com

[Paul Berry, 2015-02-24 21:58:16]

https://codereview.chromium.org/935453007/diff/1/pkg/analyzer/lib/source/pack...
File pkg/analyzer/lib/source/package_map_resolver.dart (right):

https://codereview.chromium.org/935453007/diff/1/pkg/analyzer/lib/source/pack...
pkg/analyzer/lib/source/package_map_resolver.dart:85: // TODO(paulberry): figure
out the right thing to do for Windows.
Note: AFAICT this function is broken for Windows both before and after this CL,
since it doesn't translate between '/' and '\' file separators.  In the interest
of mitigating bug 22555 as quickly as possible, I'd like to address Windows in a
separate CL.

[Paul Berry, 2015-02-24 22:04:58]

Note that this is only a partial fix to bug 22555, because it only fixes the
problem in the absence of changes to the filesystem.  In general, the mapping
from URI to file path depends on which files exist in the filesystem, so even
after this CL is applied, if files are added/deleted after analysis begins, it's
still possible for two FileBasedSource objects to be created that use the same
URI but point to different files.

[Brian Wilkerson, 2015-02-24 22:05:37]

LGTM

[Paul Berry, 2015-02-24 22:15:46]

Committed patchset #1 (id:1) manually as 44003 (presubmit successful).