bug#17053: Emacs hangs when typing in the minibuffer

[Eli Zaretskii <eliz@gnu.org>]

> From: Juanma Barranquero <lekktu@gmail.com>
> Date: Thu, 20 Mar 2014 19:01:03 +0100
> 
> Lately I've experienced a few cases of Emacs hanging while I was
> typing something in the minibuffer (most likely, when using
> describe-function or describe-variable).
> 
> Breakpoint 1 at 0x10f407d: file emacs.c, line 351.
> Temporary breakpoint 2 at 0x1117bbc: file sysdep.c, line 854.
> (gdb) bt
> #0  0x771a000d in ntdll!LdrFindResource_U () from C:\Windows\SysWOW64\ntdll.dll
> #1  0x7722f926 in ntdll!RtlQueryTimeZoneInformation () from
> C:\Windows\SysWOW64\ntdll.dll
> #2  0x2cb03a9e in ?? ()
> #3  0x00000000 in ?? ()
> 
> Lisp Backtrace:
> "read-from-minibuffer" (0x88e280)
> "completing-read-default" (0x88e5c0)
> "completing-read" (0x88e6d4)
> "byte-code" (0x88e980)
> "call-interactively" (0x88ec84)
> "electric-helpify" (0x88efc8)
> "electric-describe-function" (0x88f314)
> "call-interactively" (0x88f520)
> "command-execute" (0x88f85c)
> (gdb) thread 1
> [Switching to thread 1 (Thread 9436.0x1f1c)]
> #0  0x771b015d in ntdll!RtlEnableEarlyCriticalSectionEventCreation ()
> from C:\Windows\SysWOW64\ntdll.dll
> (gdb) bt
> #0  0x771b015d in ntdll!RtlEnableEarlyCriticalSectionEventCreation ()
> from C:\Windows\SysWOW64\ntdll.dll
> #1  0x771b015d in ntdll!RtlEnableEarlyCriticalSectionEventCreation ()
> from C:\Windows\SysWOW64\ntdll.dll
> #2  0x75f415e9 in WaitForMultipleObjectsEx () from
> C:\Windows\syswow64\KernelBase.dll
> #3  0x00000004 in ?? ()
> #4  0x0088d5d4 in ?? ()
> #5  0x74d919fc in KERNEL32!GetVolumePathNamesForVolumeNameA () from
> C:\Windows\syswow64\kernel32.dll
> #6  0x0088d5d4 in ?? ()
> #7  0x75fa086a in USER32!MessageBoxA () from C:\Windows\syswow64\user32.dll
> #8  0x00000004 in ?? ()
> #9  0x7efde000 in ?? ()
> #10 0x75fa0b69 in USER32!DdeNameService () from C:\Windows\syswow64\user32.dll
> #11 0x00000050 in ?? ()
> #12 0x0088d800 in ?? ()
> #13 0x01230585 in sys_select (nfds=4, rfds=0x88dab0, wfds=0x0,
> efds=0x0, timeout=0x88daa0, ignored=0x0) at w32proc.c:2095

If you type "finish", does this frame #13 ever return?  If it does,
please keep typing "finish", until you find a frame that doesn't.