[Bug: 21.1.13] key processing corrupted during Customize

================================================================ Dear Bug Team! What happened: When debugger is entered during customize, debug-on-error was reset, and keyboard processing became abnormal in all buffers. The keyboard was also altered such that some keys (RET, q, v) would not perform their normally assigned actions, but would attempt to auto-insert. Control-G is not one of the altered keys. To regenerate the problem: 0. Enable debug-on-error by clicking its checkbox under Options->General Options (or Troubleshooting in recent versions). Other debug options can be left disabled. 1. Start customize by typing M-x customize-variable RET (accept the default variable name as is, i.e., nil). 2. Tab to [State], press RET. At minubuffer prompt, press Control-G. Backtrace buffer will be displayed, contents starting with 'Signaling: (error "Canceled") ... '. Normally, pressing "q" in the backtrace buffer should get rid of the buffer and close the window, but surprisingly, a minibuffer message will complain about buffer being read-only. The problem state is reached at this point, i.e., some keys (e.g., RET, v, q) no longer work normally, even if you switch buffers. Cursor keys and mouse seem to be working correctly. 3. Using the mouse, re-enable debug-on-error . Keyboard processing should return back to normal, i.e., RET, v, q should work as expected in all buffers. This re-enabling step may need to be repeated as many times as necessary. 4. Keybindings during the abnormal state are listed as if they worked normally, e.g., 'q' is shown mapped to top-level . 5. The problem is unique to XEmacs, GNU Emacs behaves as expected, i.e., q quits the error backtrace, and debug-on-error remains enabled. 6. The problem appears both on the Solaris and the most recent Windows version of XEmacs (21.4.13). 7. Customize is the only application that triggers this problem. Feel free to ask me if more detail is needed. Recent keystrokes: ----------------- down down down down down down TAB RET C-g q right left q q q M-x r e p o r t - x e m a TAB BS TAB BS BS TAB BS a c s TAB BS BS BS BS BS BS BS BS BS BS C-g BS BS BS BS BS button1 button1up misc-user button1 button1up q misc-user button1 button1up q C-h v d e b u g - o n - q u i t RET right f right right down q M-x up down r e p o r t - x e TAB RET Recent messages (most recent first): ----------------------------------- Loading xemacsbug...done Loading xemacsbug... Loading find-func...done Loading find-func... Entering debugger... Buffer is read-only: #<buffer "*Backtrace*"> Entering debugger... Quit Buffer is read-only: #<buffer "*Backtrace*"> Buffer is read-only: #<buffer "*Backtrace*"> Buffer is read-only: #<buffer "*Backtrace*"> Buffer is read-only: #<buffer "*Backtrace*"> Entering debugger... To install your edits, invoke [State] and choose the Set operation To install your edits, invoke [State] and choose the Set operation To install your edits, invoke [State] and choose the Set operation Creating customization buffer...done Creating customization setup... Creating group... done Creating group state... Best regards, Mustafa Kocaturk Ericsson