[Bug 2744] New: Combobox loops endlessly if displayed by MDI child and mouse selects dropdown

[Wine Bugs]

http://bugs.winehq.org/show_bug.cgi?id=2744

Summary: Combobox loops endlessly if displayed by MDI child and
                    mouse selects dropdown
           Product: Wine
           Version: 20050211
          Platform: PC
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: major
          Priority: P2
         Component: wine-gui
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

When the following conditions are all true:
* Windows application uses MDI window
* At least one MDI child is displayed
* The MDI child displays a dropdown list (combobox without editing cap.)
* User selects with mouse (not keyboard) the combobox in order to display the
dropdown

... then the combobox starts flashing endlessly. The focus seems to alternate
between the MDI child and the colored rectangle which paints the combobox when
selected.

I searched the bug database, and bug #2147 looks like this exact same bug.
However, I can provide on demand a VisualBasic 6 sample application which
reproduces the bug. This problem occurs only when a MDI child displays the
dropdown list - SDI windows and dialogs are not affected.