[Bug 53001] New: Regression: Endless WAV crashes when moving file list sub-window

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=53001

Bug ID: 53001
           Summary: Regression: Endless WAV crashes when moving file list
                    sub-window
           Product: Wine-staging
           Version: 7.8
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: -unknown
          Assignee: [e-mail]
          Reporter: [e-mail]
                CC: [e-mail], [e-mail]
      Distribution: ---

STEPS TO REPRODUCE:
1. Download and extract Endless WAV (version 1.7.8b15 as of this writing):
https://www.bjoernbojahr.de/endlesswav.html
2. Run the extracted "EndlWav.exe" executable.
3. Once the application has launched, drag the bottom window titled "File List"
using its header bar.

RESULT: Endless WAV crashes with the following terminal output:

---
\Endless WAV\EndlWav.exe: dlls/ntdll/unix/thread.c:1737:
ntdll_set_exception_jmp_buf: Assertion `!jmp ||
!ntdll_get_thread_data()->jmp_buf' failed.
wine: Assertion failed at address F7F21549 (thread 0100), starting debugger...
\Endless WAV\EndlWav.exe: dlls/ntdll/unix/thread.c:1737:
ntdll_set_exception_jmp_buf: Assertion `!jmp ||
!ntdll_get_thread_data()->jmp_buf' failed.
0100:err:seh:NtRaiseException Unhandled exception code 80000101 flags 1 addr
0xf7f21549
---

ADDITIONAL INFO:
* The crash happens with wine-staging, but not the same version of wine-devel.
* This crash was introduced in a recent version of wine-staging. At least a
month or two ago with an earlier version of wine-staging, I was not getting
this crash.
* I can reproduce the bug in VirtualBox and with a clean .wine profile.
* Possibly related to bug #52853.
* The crash does not happen if using the OS window manager's shortcut key to
drag the window from anywhere (e.g., left Alt or left Super key).