Fix issue 9744

Fix issue 9744

Allow for debugger stack frames that have no corresponding pc descriptor
entry, i.e. the PC is not at a known safe point. In that case, we cannot
return a code location nor variables.

Fixes 9744
Committed: https://code.google.com/p/dart/source/detail?r=21175

[hausner, 2013-04-09 22:26:02]

Also contains a fix to make ddbg.dart run again after the library team removed
close() from stdin.

[Tom Ball, 2013-04-09 23:12:06]

lgtm

https://codereview.chromium.org/13948009/diff/1/tools/ddbg.dart
File tools/ddbg.dart (right):

https://codereview.chromium.org/13948009/diff/1/tools/ddbg.dart#newcode18
tools/ddbg.dart:18: var stdinListenerOrWhateverThisIs;
It's a StreamSubscription, so maybe stdinSubscription is a better name. I'm okay
with leaving the name as is, though. :-)

[hausner, 2013-04-09 23:36:32]

Thank you.

https://codereview.chromium.org/13948009/diff/1/tools/ddbg.dart
File tools/ddbg.dart (right):

https://codereview.chromium.org/13948009/diff/1/tools/ddbg.dart#newcode18
tools/ddbg.dart:18: var stdinListenerOrWhateverThisIs;
Thanks for the hint. I am tempted to leave it as is, but let's be nice :)

On 2013/04/09 23:12:06, Tom Ball wrote:
> It's a StreamSubscription, so maybe stdinSubscription is a better name. I'm
okay
> with leaving the name as is, though. :-)

[hausner, 2013-04-09 23:36:58]

Committed patchset #2 manually as r21175 (presubmit successful).