(tex-guess-main-file): Handle the case where one of the buffers is narrowed.

diff --git a/lisp/textmodes/tex-mode.el b/lisp/textmodes/tex-mode.el
index 465cb98c047068ac3dbc2b2bf9666c7f957b215a..43a26cf2296671f7fb30e716183c0f39f82acd71 100644 (file)
--- a/lisp/textmodes/tex-mode.el
+++ b/lisp/textmodes/tex-mode.el
@@ -1410,8 +1410,10 @@ ALL other buffers."
                     ;; (or (easy-mmode-derived-mode-p 'latex-mode)
                     ;;          (easy-mmode-derived-mode-p 'plain-tex-mode))
                     (save-excursion
-                      (goto-char (point-min))
-                      (re-search-forward header-re 10000 t)))
+                      (save-restriction
+                        (widen)
+                        (goto-char (point-min))
+                        (re-search-forward header-re 10000 t))))
            (throw 'found (expand-file-name buffer-file-name))))))))
 
 (defun tex-main-file ()