bug#20685: 2015-04-19; args-out-of-range error when no newline at eob.

[Nicolas Richard]

Hi,

This one often bites me when I'm in a narrowed buffer.

Here's a backtrace from a minimal recipe (which is in the backtrace).

Debugger entered--Lisp error: (args-out-of-range #<buffer temp> 57 58)
  buffer-substring-no-properties(57 58)
  LaTeX-backward-paragraph()
  LaTeX-fill-region(41 57 nil " environment document")
  LaTeX-fill-environment(nil)
  call-interactively(LaTeX-fill-environment)
  (let ((data 
"\\documentclass{minimal}\n\\begin{document}\n\n\\end{document}")) 
(switch-to-buffer (get-buffer-create "temp")) (TeX-latex-mode) (insert data) 
(search-backward "\n\n") (call-interactively (quote LaTeX-fill-environment)))
  eval-buffer(#<buffer  *load*> nil 
"/home/youngfrog/tmp-test-auctex-filling.el" nil t)  ; Reading at buffer 
position 319
  load-with-code-conversion("/home/youngfrog/tmp-test-auctex-filling.el" 
"/home/youngfrog/tmp-test-auctex-filling.el" nil t)
  load("/home/youngfrog/tmp-test-auctex-filling.el" nil t)
  command-line-1(("-l" "/home/youngfrog/tmp-test-auctex-filling.el"))
  command-line()
  normal-top-level()

I suggest the following change:

--8<---------------cut here---------------start------------->8---
modified   latex.el
@@ -4475,10 +4475,7 @@ If COUNT is non-nil, do it COUNT times."
                                                "address@hidden|[ \t]*\\($\\|"
                                                TeX-comment-start-regexp "\\)"))
                            (progn
-                             (when (string= (buffer-substring-no-properties
-                                             (point) (+ (point)
-                                                        (length TeX-esc)))
-                                            TeX-esc)
+                             (when (looking-at (regexp-quote TeX-esc))
                                (goto-char (TeX-find-macro-end)))
                              (forward-line 1)
                              (when (< (point) start)
--8<---------------cut here---------------end--------------->8---