[AUCTeX] Inverse search with Emacs/AUCTeX

[Alan Ristow]

A couple of us on the MiKTeX users list have been having a problem with
Emacs/AUCTeX and inverse search from the DVI viewer Yap. We're both 
using the Emacs 22/AUCTeX 11.83 bundle.

Inverse search works fine if the entire document is contained in a 
single file. That is, if I have a file called article.tex that uses no 
\input or \include commands then I have no problem with inverse search. 
However, if I use \input or \include commands I have problems. Suppose I 
say:

\input{mychapter}

LaTeX, of course, reads this and searches for a file called 
mychapter.tex to add to the document. If I do an inverse search on a 
piece of text from mychapter.tex, however, Emacs creates a new buffer 
called mychapter (without the .tex extension) and the inverse search 
ends in this empty buffer.

We tracked the problem to the source special embedded in the DVI, which 
itself does not have the .tex extension (e.g., c:\files\mychapter). 
Thus, the filename provided to Emacs during the inverse search does not 
have the .tex extension, and unless AUCTeX or Emacs adds it implicitly 
it seems that Emacs cannot possibly find the correct file.

The inverse search command I am using is:

gnuclientw.exe -F +%l "%f"

(In the Windows version of gnuclient the -F switch pops the Emacs window 
to the top of all the other windows.) If I say:

\input{mychapter.tex}

inverse search works correctly with Emacs. That is, it loads the file 
mychapter.tex into a buffer and selects the correct line. While this is 
a useful workaround, it is at odds with LaTeX convention to leave the 
file extension off.

By way of comparison, WinEdt opens the correct file and finds the 
appropriate line with no problem whether I use \input{mychapter} or 
\input{mychapter.tex}. FWIW, the inverse search command line for WinEdt is:

winedt.exe "[Open(|%f|);SelPar(%l,8)]"

This is exactly analogous to the gnuclient command line above, but 
WinEdt seems to compensate for the implied .tex extension.

The two of us who are discussing this are both using the new MiKTeX 2.5 
and I have no idea whether this was a problem under MiKTeX 2.4. The 
other user having this problem reported it as a MiKTeX bug, but was told 
by MiKTeX developer Christian Schenk that embedding source specials as 
written in the \input command (i.e., without the .tex extension unless 
explicitly written) is in keeping with the LaTeX specification and that 
this is therefore not a bug in MiKTeX.

So is this an Emacs/AUCTeX bug? Is there a setting that I've missed (or 
perhaps undone with something I've put in my .emacs file)?

Alan