bug#16751: 24.3.50; Export during Org export to HTML

[Eli Zaretskii <eliz@gnu.org>]

> From: "Sebastien Vauban" <sva-news@mygooglest.com>
> Cc: 16751@debbugs.gnu.org
> Date: Tue, 18 Feb 2014 12:39:34 +0100
> 
> > Nonetheless, since you say you can reproduce this, please provide the
> > information requested below, in case the underlying reason is still
> > valid:
> >
> >> Thread 1 (Thread 604.0x4fb4):
> >> #0  0x77ae9bfd in KERNELBASE!DebugBreak () from /cygdrive/c/Windows/SYSTEM32/KERNELBASE.dll
> >> #1  0x011ec39c in emacs_abort () at c:/msys/home/dani/emacs/repo/src/w32fns.c:7984
> >> #2 0x01122321 in Fexpand_file_name (name=100535361,
> >> default_directory=96023889) at c:/msys/home/dani/emacs/repo/src/fileio.c:1450
> >
> > In this frame #2, the one in Fexpand_file_name, please show the result
> > of these commands:
> >
> >  (gdb) source .gdbinit
> >
> > If you don't have a .gdbinit file, you can find it here:
> >
> >   http://bzr.savannah.gnu.org/lh/emacs/trunk/annotate/head:/src/.gdbinit
> 
> Took that one.
> 
> Though:
> 
> --8<---------------cut here---------------start------------->8---
> $ gdb -p 9012
> GNU gdb (GDB) 7.6.50.20130728-cvs (cygwin-special)
> Copyright (C) 2013 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "i686-pc-cygwin".
> Type "show configuration" for configuration details.
> For bug reporting instructions, please see:
> <http://www.gnu.org/software/gdb/bugs/>.
> Find the GDB manual and other documentation resources online at:
> <http://www.gnu.org/software/gdb/documentation/>.
> For help, type "help".
> Type "apropos word" to search for commands related to "word".
> 
> Attaching to process 9012
> [New Thread 9012.0x1b80]
> [New Thread 9012.0xf34]
> [New Thread 9012.0x13b0]
> [New Thread 9012.0x22d8]
> [New Thread 9012.0x16c4]
> [New Thread 9012.0x4ec]
> [New Thread 9012.0x1ad0]
> [New Thread 9012.0x714]
> [New Thread 9012.0xb08]
> [New Thread 9012.0x1d7c]
> [New Thread 9012.0xd44]
> [New Thread 9012.0x224c]
> [New Thread 9012.0x2020]
> [New Thread 9012.0xac8]
> /cygdrive/d/Users/sva/.gdbinit:19: Error in sourced command file:
> No symbol table is loaded.  Use the "file" command.
> [New Thread 9012.0xcf0]
> Reading symbols from /cygdrive/c/Program Files (x86)/emacs-r114715-20131019-w32/bin/emacs.exe...done.
> --8<---------------cut here---------------end--------------->8---
> 
> Is the above warning to be expected?
> 
> Line 19 is the line beginning with "set":
> 
> --8<---------------cut here---------------start------------->8---
> # Force loading of symbols, enough to give us VALBITS etc.
> set $dummy = main + 8
> --8<---------------cut here---------------end--------------->8---

Not sure why this happens, but let's ignore this for the moment.

> (gdb) p name
> No symbol "name" in current context.
> --8<---------------cut here---------------end--------------->8---
> 
> I don't know what the above means.

You are not in the correct stack frame.  You need to be in Thread 1 in
frame #2:

  Thread 1 (Thread 9012.0x1b80):
  #0  0x77149bfd in KERNELBASE!DebugBreak () from /cygdrive/c/Windows/SYSTEM32/KERNELBASE.dll
  #1  0x011ec39c in emacs_abort () at c:/msys/home/dani/emacs/repo/src/w32fns.c:7984
  #2  0x01122321 in Fexpand_file_name (name=157735393, default_directory=157801377) at c:/msys/home/dani/emacs/repo/src/fileio.c:1450

So:

  (gdb) thread 1
  (gdb) frame 2
  (gdb) p name
  (gdb) xstring
  (gdb) p default_directory
  (gdb) xtype

> Anyway, I was still able to call "xbacktrace":
> 
> --8<---------------cut here---------------start------------->8---
> (gdb) xbacktrace
> "expand-file-name" (0x8859e0)
> "concat" (0x885b24)
> "setq" (0x885c44)
> "cond" (0x885d94)
> "cond" (0x885ee4)
> "let*" (0x886024)
> "org-html-link" (0x8861c4)

Thanks.  This tells a lot, but I still need that info from
Fexpand_file_name.

> > Alternatively, if you can find where in Lisp is this expand-file-name
> > call, add 'message' there, or step through that code with Edebug, to
> > show the arguments passed to expand-file-name.
> 
> It seems to be in `org-html-link', and there's only one call to
> `expand-file-name', when the path begins by "file:".
> 
> I've looked at all my "file:" links in the buggy Org document. One such
> line came out as very different from the others:
> 
> --8<---------------cut here---------------start------------->8---
> URI=file:///opt/tomcat/4/apache-tomcat-4.1.40/webapps/../user_projects/GHIJSP2/deploy/WEB-INF/sharedfiles/resources/FR/domVal.xml
> --8<---------------cut here---------------end--------------->8---
> 
> If I remove that line from my Org document, Emacs doesn't crash
> anymore...

How come you have such a file URI on a Windows machine?  Where does
this point to?

Also, what does org-element-property return for this file name (that's
the argument passed to expand-file-name, I think)?