Bug 7122 - Forms eventually paint incorrectly
Summary: Forms eventually paint incorrectly
Status: NEW
Alias: None
Product: Class Libraries
Classification: Mono
Component: Windows.Forms ()
Version: 2.10.x
Hardware: PC Linux
: Lowest normal
Target Milestone: Community
Assignee: Bugzilla
Depends on:
Reported: 2012-09-12 20:59 UTC by Greg Odom
Modified: 2017-09-01 11:55 UTC (History)
1 user (show)

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

A test program and scrript. clickit.sh uses xdotool for automation. (9.98 KB, application/x-compressed-tar)
2012-09-12 20:59 UTC, Greg Odom

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Description Greg Odom 2012-09-12 20:59:30 UTC
Created attachment 2516 [details]
A test program and scrript.  clickit.sh uses xdotool for automation.

After repeated use, System.Windows.Forms.Form will not paint all of its controls.  A test case is included which works as follows:

*) Form 1 is the main form.  Clicking on the button "Dialog" brings up Form 2.
*) Form 2 has two buttons that hide the form and focus is returned to Form 1.
*) After Form 2 is hidden and shown thousands of times, the hide button that was being clicked will no longer paint.
*) A script is included that uses xdotool to automatically show and hide Form 2.

After the painting error, Form 2 can be closed by the other hide button or through the window manager.  But at this point, the Mono instance is broken.  Over time, Form 2 will have fewer and fewer of its controls painted.  In many cases, one click on the "Dialog" button on Form 1 will bring up multiple Form 2's.  Only one of these Form 2's will have the correct title, shape, and location.  The others are malformed.  Closing a malformed Form 2 will crash the app.    From what I can see, I don't believe that the problem is in X.  Mono acts as though the controls were removed or hidden on the form.