705454 - Loading of module PMMERGE to compute screen size is wrong

Status: RESOLVED FIXED

(Core Graveyard :: Widget: OS/2, defect)

Description

[Erdmann]

User Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; Tablet PC 2.0; .NET4.0C; MALC)




Expected results:

http://dxr.mozilla.org/mozilla/mozilla-central/widget/src/os2/nsScreenOS2.cpp.html: 

routine "nsScreenOS2 :: GetAvailRect": this routine uses DosLoadModule, DosQueryProcAddress, DosFreeModule to get a function pointer to function to query screen size. However the module is freed before function pointer is actually used.
Since PMMERGE module is always loaded (if PM is loaded which is prerequisite for any graphical app) I suggest to replace with:

  if ( !rc && !pfnQueryDesktopWorkArea )
  {
      HMODULE hmod = 0;
      rc = DosQueryModuleHandle("PMMERGE", &hmod );
      if ( !rc )
      {
          rc = DosQueryProcAddr( hmod, 5469, NULL, (PFN*) &pfnQueryDesktopWorkArea ); // WinQueryDesktopWorkArea
      }
  }
if ( pfnQueryDesktopWorkArea && !rc )
...

Comment 1

[Dave Yeo]

Attachment: Patch based on Lars comment

Lars, does this look correct?
I'll have to do a test build before asking for review.

Comment 2

[Dave Yeo]

Attachment: Patch based on Lars comment, with missed DosQueryModuleHandle()

Comment 3

[Erdmann]

Yes, your suggested fix is OK.

Comment 4

[Dave Yeo]

Comment on attachment 577161 [details] [diff] [review]
Patch based on Lars comment, with missed DosQueryModuleHandle()

I've run this for a week with no adverse affects. SeaMonkey opens where it should without interfering with Warpcentre

Comment 5

[Dão Gottwald [:dao]]

http://hg.mozilla.org/integration/mozilla-inbound/rev/dbe04a04bc41

Comment 6

[Matt Brubeck (:mbrubeck)]

https://hg.mozilla.org/mozilla-central/rev/dbe04a04bc41