From 31489a32f575cb5cfcd8748355f46ae2afcc4436 Mon Sep 17 00:00:00 2001
From: Juri Linkov <juri@jurta.org>
Date: Sun, 16 Jun 2013 01:44:38 +0300
Subject: [PATCH] * lisp/files-x.el (modify-file-local-variable-prop-line): Add
 local variables to the end of the existing comment on the first line. Use
 `file-auto-mode-skip' to skip interpreter magic line, and also skip XML
 declaration.

---
 lisp/ChangeLog  |  7 +++++++
 lisp/files-x.el | 41 +++++++++++++++++++++++++++++++----------
 2 files changed, 38 insertions(+), 10 deletions(-)

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 919772659ea..f7f42011575 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,10 @@
+2013-06-15  Juri Linkov  <juri@jurta.org>
+
+	* files-x.el (modify-file-local-variable-prop-line): Add local
+	variables to the end of the existing comment on the first line.
+	Use `file-auto-mode-skip' to skip interpreter magic line,
+	and also skip XML declaration.
+
 2013-06-15  Stefan Monnier  <monnier@iro.umontreal.ca>
 
 	* startup.el (package--builtin-versions): New var.
diff --git a/lisp/files-x.el b/lisp/files-x.el
index 0ba245d423a..2ae1a0e4045 100644
--- a/lisp/files-x.el
+++ b/lisp/files-x.el
@@ -256,19 +256,40 @@ from the -*- line ignoring the input argument VALUE."
 
 	(goto-char (point-min))
 
-	;; Skip interpreter magic line "#!"
-	(when (looking-at "^\\(#!\\|'\\\\\"\\)")
+	;; Skip interpreter magic line "#!" or XML declaration.
+	(when (or (looking-at file-auto-mode-skip)
+		  (looking-at "<\\?xml[^>\n]*>$"))
 	  (forward-line 1))
 
+	(comment-normalize-vars)
 	(let ((comment-style 'plain)
-	      (comment-start (or comment-start ";;; ")))
-	  (comment-region
-	   (prog1 (point)
-	     (insert "-*-")
-	     (setq beg (point-marker))
-	     (setq end (point-marker))
-	     (insert "-*-\n"))
-	   (point))))
+	      (comment-start (or comment-start ";;; "))
+	      (line-beg (line-beginning-position))
+	      (ce nil))
+	  ;; If the first line contains a comment.
+	  (if (save-excursion
+		(and (looking-at comment-start-skip)
+		     (goto-char (match-end 0))
+		     (re-search-forward comment-end-skip)
+		     (goto-char (match-beginning 0))
+		     ;; Still on the same line?
+		     (equal line-beg (line-beginning-position))
+		     (setq ce (point))))
+	      ;; Add local variables to the end of the existing comment.
+	      (progn
+		(goto-char ce)
+		(insert "  -*-")
+		(setq beg (point-marker))
+		(setq end (point-marker))
+		(insert "-*-"))
+	    ;; Otherwise, add a new comment before the first line.
+	    (comment-region
+	     (prog1 (point)
+	       (insert "-*-")
+	       (setq beg (point-marker))
+	       (setq end (point-marker))
+	       (insert "-*-\n"))
+	     (point)))))
 
       (cond
        ((looking-at "[ \t]*\\([^ \t\n\r:;]+\\)\\([ \t]*-\\*-\\)")
-- 
2.39.2