Contents of NSAlert not visible until window is moved on WINDOWS

[gnustep-admin]

When I run the SCSI2SD app I am working on... when an NSAlert is shown, it's contents are not visible until I move the alert panel, I am not sure why this is happening.

[DTW-Thalion]

This does not reproduce here. Tested on Windows against libs-gui master 5ce9650 with the win32 backend from gnustep-back 0.32.0 and gnustep-base 1.31.1, built with clang on MSYS2 UCRT64.

An NSAlert with a message text, an informative text and one button, shown with runModal, draws its contents straight away. Tried both from main before the application loop starts, and from a timer while the application is already running its event loop with a window of its own on screen. In both cases the panel is left alone once it appears, with no raise and no move, and a capture of the desktop three seconds later shows the icon, both text fields and the button. A second capture, after moving the panel 40 pixels with MoveWindow, shows the same contents.

One defect did come out of it. The panel's frame view and content view still report needsDisplay after the contents have drawn. The separator in the panel is an NSBox two pixels high, so its content view ends up zero pixels high, and a subview with no area is never reached by the display walk, never clears its mark, and passes that mark up to every view above it. PR #867 fixes that, and is set to close this as the one thing found on this path.

If you still see the original symptom on a current build, reopen and say whether the alert goes up inside a nested modal session, and whether the application sets a theme.