Re: old bootstrap error emerges again

[Eli Zaretskii <eliz@gnu.org>]

> From: Dieter Deyke <deyke@comcast.net>
> Cc: emacs-pretest-bug@gnu.org, emacs-devel@gnu.org
> Date: Sat, 25 Mar 2006 08:54:45 -0700
> 
> The strange thing is that the error vanished yesterday on my work PC,
> but using the same tools I still get it on my home PC:

Do you have the same sources (i.e. the same CVS check-out) on both of
these machines?

> Starting program: C:\Users\deyke\emacs-build\work\lisp/../bin/my-emacs.exe -batc
> h --no-init-file --no-site-file --multibyte -f batch-byte-compile url/vc-dav.el
> 
> Breakpoint 3, get_doc_string (filepos=-2581128, unibyte=0, definition=0)
>     at doc.c:196
> 196             error ("Cannot open doc string file \"%s\"", name);
> (gdb) up 1
> #1  0x0110da05 in Fdocumentation (function=27819993, raw=27674673) at doc.c:456
> 456           tem = get_doc_string (doc, 0, 0);
> (gdb) print function
> $1 = 27819993
> (gdb) xtype
> Lisp_Symbol
> (gdb) xsymbol
> $2 = (struct Lisp_Symbol *) 0x1a87fd8
> "file-exists-p"
> (gdb)

Thanks.  Now please repeat this again, and this time put a breakpoint
in Fdocumentation; when it breaks, verify that the first argument is
indeed file-exists-p, and then step through the code until it calls
get_doc_string and tell me what you saw.  When I do that on my system,
what I see is below.  As you see, Fdocumentation returns nil without
ever calling get_doc_string.  Can you find out what is different on
your machine, and why?

> As for your last question, I'm not using MSYS. My setup includes:
> 
> english XP Pro SP2
> current cygwin
> MinGW-3.1.0-1 in PATH before cygwin

Okay, so perhaps Cygwin has something to do with this.  Hopefully, we
will understand that when we find the reason for the different
behavior.

Here's a transcript of the GDB session on my machine:

D:\gnu\test\emacs\lisp>gdb ../bin/bootstrap-emacs.exe
GNU gdb 6.3
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i686-pc-mingw32"...
(gdb) br Fdocumentation
Breakpoint 1 at 0x10fc4e0: file doc.c, line 378.
(gdb) source ../src/.gdbinit
Environment variable "DISPLAY" not defined.
Environment variable "TERM" not defined.
Breakpoint 2 at 0x1133856: file w32fns.c, line 8965.
Breakpoint 3 at 0x109513b: file sysdep.c, line 1395.
(gdb) del 2 3
(gdb) r -batch  --no-init-file --no-site-file --multibyte -l loaddefs.el -f batc
h-byte-compile url/vc-dav.el
Starting program: D:\gnu\test\emacs\lisp/../bin/bootstrap-emacs.exe -batch  --no
-init-file --no-site-file --multibyte -l loaddefs.el -f batch-byte-compile url/v
c-dav.el
Loading subst-ksc...
Loading subst-gb2312...
Loading subst-big5...
Loading subst-jis...

Breakpoint 1, Fdocumentation (function=44196825, raw=44054577) at doc.c:378
378       int try_reload = 1;
(gdb) p function
$1 = 44196825
(gdb) xtype
Lisp_Symbol
(gdb) xsymbol
$2 = (struct Lisp_Symbol *) 0x2a263d8
"file-exists-p"
(gdb) n
374     {
(gdb) n
384       if (SYMBOLP (function)
(gdb)
382       doc = Qnil;
(gdb)
384       if (SYMBOLP (function)
(gdb)
382       doc = Qnil;
(gdb)
384       if (SYMBOLP (function)
(gdb)
389       fun = Findirect_function (function, Qnil);
(gdb)
390       if (SUBRP (fun))
(gdb)
392           if (XSUBR (fun)->doc == 0)
(gdb)
409             return Qnil;
(gdb)
477     }
(gdb)