Bug 34753 - Mono C# compiler incorrectly outputs CS0019 with reference equality to (null)
Summary: Mono C# compiler incorrectly outputs CS0019 with reference equality to (null)
Alias: None
Product: Compilers
Classification: Mono
Component: C# ()
Version: 4.0.0
Hardware: Macintosh Mac OS
: --- normal
Target Milestone: ---
Assignee: Marek Safar
Depends on:
Reported: 2015-10-11 12:13 UTC by Stephen Darnell
Modified: 2015-10-12 13:00 UTC (History)
1 user (show)

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

Test file showing problem. (154 bytes, application/octet-stream)
2015-10-11 12:13 UTC, Stephen Darnell
Attachment with text/plain mime format (154 bytes, text/plain)
2015-10-11 12:15 UTC, Stephen Darnell

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Description Stephen Darnell 2015-10-11 12:13:51 UTC
Created attachment 13277 [details]
Test file showing problem.

MCS incorrectly outputs CS0019 when comparing a reference against (null) in brackets.

See the attached test file with the following lines:
    Wibble w = new Wibble();
    if (w == (null)) ...

This produces:
$ mcs test.cs
test.cs(6,9): error CS0019: Operator `==' cannot be applied to operands of type `Wibble' and `null'
Compilation failed: 1 error(s), 0 warnings

Without the brackets around the null the code compiles without any error.

Obviously this test case is the smallest example I could produce and is easily modified to compile.
But the real life situation is a bit more complicated and involves generated code so it is a little tricky to 'just remove the brackets', but if this issue could be fixed, that would be great. Thanks.

OS: Mac OS-X 10.10.5
Mono: Mono JIT compiler version 4.0.4
MCS: Mono C# compiler version
Comment 1 Stephen Darnell 2015-10-11 12:15:19 UTC
Created attachment 13278 [details]
Attachment with text/plain mime format
Comment 2 Marek Safar 2015-10-12 13:00:18 UTC
Fixed in master