[Bug 51363] New: user32:dde times out on cw-*-1507 machines, pollutes other tests

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=51363

Bug ID: 51363
           Summary: user32:dde times out on cw-*-1507 machines, pollutes
                    other tests
           Product: Wine
           Version: 6.10
          Hardware: x86-64
                OS: Windows
            Status: NEW
          Severity: normal
          Priority: P2
         Component: user32
          Assignee: [e-mail]
          Reporter: [e-mail]

The timeouts are not systematic but still pretty frequent:

https://test.winehq.org/data/patterns.html#user32:dde

0a24:dde: 82 tests executed (0 marked as todo, 0 failures), 0 skipped.
user32:dde:0220 done (258) in 120s

They happen on the same set of machines as the user32:sysparams timeouts (bug
51362) so they are likely to share a common cause: a rogue window that does not
process some broadcast message.

A side effect of the timeout is that subprocesses started by user32:dde
terminate late and issue a test failure while other tests are running. For
instance:

wave.c:1223: waveOutOpen(WAVE_MAPPER): WAVE_FORMAT_IMA_ADPCM not supported
dde.c:1015: Test failed: Unhandled msg: 000003e1
Misplaced failure line
03bc:dde: 28 tests executed (0 marked as todo, 1 failure), 0 skipped.
wave.c:1599: writing 44101 bytes then 44099 bytes