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

[Sebastien Vauban]

Eli Zaretskii wrote:
> 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

Thanks for these step-by-step commands... Applied with the following
Org file which allows me to reproduce the crash:

--8<---------------cut here---------------start------------->8---
* Config

Put this in your config file:

URI=file:///opt/tomcat/4/apache-tomcat-4.1.40/webapps/../user_projects/GHIJSP2/deploy/WEB-INF/sharedfiles/resources/FR/domVal.xml
Line=35: Attribute "fDel" must be declared for element type "pair".
--8<---------------cut here---------------end--------------->8---

And the info you want:

--8<---------------cut here---------------start------------->8---
(gdb) thread 1
[Switching to thread 1 (Thread 3868.0x1098)]
#0  0x77149bfd in KERNELBASE!DebugBreak () from 
/cygdrive/c/Windows/SYSTEM32/KERNELBASE.dll
(gdb) frame 2
#2  0x01131397 in Fexpand_file_name (name=107130897, 
default_directory=99518353) at c:/msys/home/dani/emacs/trunk/src/fileio.c:1484
1484      c:/msys/home/dani/emacs/trunk/src/fileio.c: No such file or directory.
(gdb) p name
$1 = 107130897
(gdb) xstring
(gdb) source ~/.gdbinit
Warning: /cygdrive/c/Program Files (x86)/emacs-trunk/bin/../lwlib: No such file 
or directory.
SIGINT is used by the debugger.
Are you sure you want to change it? (y or n) [answered Y; input not from 
terminal]
Environment variable "DISPLAY" not defined.
TERM = xterm-256color
Breakpoint 1 at 0x10f0372: file c:/msys/home/dani/emacs/trunk/src/emacs.c, line 
351.
Temporary breakpoint 2 at 0x1113e88: file 
c:/msys/home/dani/emacs/trunk/src/sysdep.c, line 854.
(gdb) xstring
$2 = (struct Lisp_String *) 0x662b010
"///opt/tomcat/4/apache-tomcat-4.1.40/webapps/../user_projects/GHIJSP2/deploy/WEB-INF/sharedfiles/resources/FR/domVal.xml"
(gdb) p default_directory
$3 = 99518353
(gdb) xtype
Lisp_String
(gdb)
--8<---------------cut here---------------end--------------->8---

>>> 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?

It does not point to anything sensible, at least not from my machine.

It's a line of code which I have to copy in some Apache configuration
file (on a testing server) and which I inserted verbatim in my Org
file.

Admittedly, I should put such line in a #+begin/end_example block --
and, FYI, that doesn't crash Emacs. But I didn't in my real file, and
had the crash when exporting, hence this bug report.

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

I tried to eval (org-element-property) on the file name, in the above
Org file:

--8<---------------cut here---------------start------------->8---
Debugger entered--Lisp error: (wrong-number-of-arguments (lambda (property 
element) "Extract the value from the PROPERTY of an ELEMENT." (if (stringp 
element) (get-text-property 0 property element) (plist-get (nth 1 element) 
property))) 0)
  org-element-property()
  eval((org-element-property) nil)
  eval-expression((org-element-property) nil)
  call-interactively(eval-expression nil nil)
  command-execute(eval-expression)
--8<---------------cut here---------------end--------------->8---

Not what you wanted, for sure.

Best regards,
  Seb