[Bug 17431] New: SPY_DumpMem shouldn't crash when given an invalid pointer

http://bugs.winehq.org/show_bug.cgi?id=17431

Summary: SPY_DumpMem shouldn't crash when given an invalid
                    pointer
           Product: Wine
           Version: 1.1.15
          Platform: Other
               URL: http://test.winehq.org/data/3fa05ae6a7c08f9534badfeffbe0
                    2db9e00ab47a/wine_xp_ae-ub810-all/comctl32:datetime.html
        OS/Version: other
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P2
         Component: user32
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

The linked test was run by Austin English with WINEDEBUG=+all.

The line in the test that caused the crash was probably this one, or a similar
line:
http://source.winehq.org/git/wine.git/?a=blob;f=dlls/comctl32/tests/datetime...

The test is sending DTM_SETMCCOLOR, which has lParam as a COLORREF.
SPY_DumpStructure is checking for several LVM_ messages that have a pointer in
lParam. Apparently, DTM_SETMCCOLOR has the same value as one of those other
symbols, and our message spy code can't tell the difference.

I don't think we can avoid this situation, but it shouldn't crash. SPY_DumpMem
should be able to catch page faults.