Subject: Re: bug#38038: 27.0.50; Emacs freezes opening tabs.

From: Eli Zaretskii <[email-masked]>
Date: Sat, 09 Nov 2019 10:28:45 +0200

> Cc: Juri Linkov <[email-masked]>, Eli Zaretskii <[email-masked]>,
>  [email-masked]
> From: martin rudalics <[email-masked]>
> Date: Sat, 9 Nov 2019 09:09:13 +0100
> 
> Here on Windows the latter form hangs on line 2516 of w32term.c
> 
> 		  Lisp_Object val
> 		    = buffer_local_value (Qunderline_minimum_offset,
> 		                          s->w->contents);
> 
> which continuously tries to signal an error with the backtrace
> 
> #0  xsignal2 (error_symbol=XIL(0xfd80), arg1=XIL(0x32d0), arg2=XIL(0)) at ../../src/eval.c:1713
> #1  0x00000004002dcaa5 in wrong_type_argument (predicate=XIL(0x32d0), value=XIL(0)) at ../../src/data.c:155

And the error says that the window has no buffer, is that right?

> where frame #3 indicates that we probably should avoid asking for a buffer
> local value in a pseudo window.  Right?

Yes.  Does adding that fix the problem, including the original one
with the tab bar?