Bug 5099 - Variable inside loop inside iteration method not properly closed over
Summary: Variable inside loop inside iteration method not properly closed over
Alias: None
Product: Compilers
Classification: Mono
Component: C# ()
Version: unspecified
Hardware: PC Windows
: --- normal
Target Milestone: ---
Assignee: Marek Safar
Depends on:
Reported: 2012-05-15 16:03 UTC by Brett Ernst
Modified: 2012-05-16 14:41 UTC (History)
1 user (show)

Is this bug a regression?: ---
Last known good build:

Small repro (639 bytes, text/plain)
2012-05-15 16:03 UTC, Brett Ernst

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Description Brett Ernst 2012-05-15 16:03:25 UTC
Created attachment 1894 [details]
Small repro

It appears that when you close over a variable inside a loop that is, in turn, inside an iterator method, the variable is not properly scoped and may end up with the wrong value when the delegate is called. This is a bit convoluted, but see the attached repro.

Compiled in .NET 3.5/4.0/4.5, the output is "foo", but in Mono 2.10.x, the output is "bar".

Apologies if this was fixed already in 2.11; I don't have access to that version at the moment. I know the foreach closure behavior has changed, but I'm not sure if this is related to its use inside an iterator method.
Comment 1 Marek Safar 2012-05-16 14:41:41 UTC
Already fixed in master (most likely 2.11 too but didn't test it)