org-e-latex: Fix publishing problems when compiling a TeX file

* contrib/lisp/org-e-latex.el (org-e-latex-compile): Fix compilation
  when default-directory from current buffer doesn't match directory
  from file being compiled. Small refactoring, too.

Thanks to Robert Klein for reporting the problem and suggesting a fix.

contrib/lisp/org-e-latex.el

@@ -2667,13 +2667,14 @@ TEXFILE is the name of the file being compiled.  Processing is
 done through the command specified in `org-e-latex-pdf-process'.
 
 Return PDF file name or an error if it couldn't be produced."
-  (let* ((wconfig (current-window-configuration))
-	 (texfile (file-truename texfile))
+  (let* ((texfile (file-truename texfile))
 	 (base (file-name-sans-extension texfile))
+	 ;; Make sure `default-directory' is set to TEXFILE directory,
+	 ;; not to whatever value the current buffer may have.
+	 (default-directory (file-name-directory texfile))
 	 errors)
     (message (format "Processing LaTeX file %s ..." texfile))
-    (unwind-protect
-	(progn
+    (save-window-excursion
       (cond
        ;; A function is provided: Apply it.
        ((functionp org-e-latex-pdf-process)
@@ -2682,7 +2683,7 @@ Return PDF file name or an error if it couldn't be produced."
        ;; values in each command before applying it.  Output is
        ;; redirected to "*Org PDF LaTeX Output*" buffer.
        ((consp org-e-latex-pdf-process)
-	    (let* ((out-dir (or (file-name-directory texfile) "./"))
+	(let* ((out-dir (file-name-directory texfile))
 	       (outbuf (get-buffer-create "*Org PDF LaTeX Output*")))
 	  (mapc
 	   (lambda (command)
@@ -2714,8 +2715,7 @@ Return PDF file name or an error if it couldn't be produced."
 			   (if (not errors) "."
 			     (concat " with errors: " errors)))))
 	;; Return output file name.
-	    pdffile))
-      (set-window-configuration wconfig))))
+	pdffile))))
 
 (defun org-e-latex--collect-errors (buffer)
   "Collect some kind of errors from \"pdflatex\" command output.