(generate-autoload-section-header): Doc fix.

(update-file-autoloads): Use autoload-read-section-header.
(update-autoloads-from-directories): Likewise.
(generate-autoload-section-continuation): New variable.
(autoload-read-section-header): New function.
(update-file-autoloads): Don't call save-buffer if no changes.
(generate-file-autoloads): Split the section header line
into multiple comments.

1 files changed, 42 insertions, 9 deletions

diff --git a/lisp/emacs-lisp/autoload.el b/lisp/emacs-lisp/autoload.el
index 1a85cd7c688..1bce589cc8c 100644
--- a/lisp/emacs-lisp/autoload.el
+++ b/lisp/emacs-lisp/autoload.el
@@ -51,12 +51,14 @@ read and an autoload made for it.  If there is further text on the line,
 that text will be copied verbatim to `generated-autoload-file'.")
 
 (defconst generate-autoload-section-header "\f\n;;;### "
-  "String inserted before the form identifying
-the section of autoloads for a file.")
+  "String that marks the form at the start of a new file's autoload section.")
 
 (defconst generate-autoload-section-trailer "\n;;;***\n"
   "String which indicates the end of the section of autoloads for a file.")
 
+(defconst generate-autoload-section-continuation ";;;;;; "
+  "String to add on each continuation of the section header form.")
+
 (defun make-autoload (form file)
   "Turn FORM into an autoload or defvar for source file FILE.
 Returns nil if FORM is not a defun, define-skeleton, defmacro or defcustom."
@@ -132,6 +134,27 @@ Returns nil if FORM is not a defun, define-skeleton, defmacro or defcustom."
   (file-relative-name file
                       (file-name-directory generated-autoload-file)))
 
+(defun autoload-read-section-header ()
+  "Read a section header form.
+Since continuation lines have been marked as comments,
+we must copy the text of the form and remove those comment
+markers before we call `read'."
+  (save-match-data
+    (let ((beginning (point))
+          string)
+      (forward-line 1)
+      (while (looking-at generate-autoload-section-continuation)
+        (forward-line 1))
+      (setq string (buffer-substring beginning (point)))
+      (with-current-buffer (get-buffer-create " *autoload*")
+        (erase-buffer)
+        (insert string)
+        (goto-char (point-min))
+        (while (search-forward generate-autoload-section-continuation nil t)
+          (replace-match " "))
+        (goto-char (point-min))
+        (read (current-buffer))))))
+
 (defun generate-file-autoloads (file)
   "Insert at point a loaddefs autoload section for FILE.
 autoloads are generated for defuns and defmacros in FILE
@@ -269,12 +292,24 @@ are used."
         (setq output-end (point-marker))))
     (if done-any
         (progn
+          ;; Insert the section-header line
+          ;; which lists the file name and which functions are in it, etc.
           (insert generate-autoload-section-header)
           (prin1 (list 'autoloads autoloads-done load-name
                        (autoload-trim-file-name file)
                        (nth 5 (file-attributes file)))
                  outbuf)
           (terpri outbuf)
+          ;; Break that line at spaces, to avoid very long lines.
+          ;; Make each sub-line into a comment.
+          (with-current-buffer outbuf
+            (save-excursion
+              (forward-line -1)
+              (while (not (eolp))
+                (move-to-column 64)
+                (skip-chars-forward "^ \n")
+                (or (eolp)
+                    (insert "\n" generate-autoload-section-continuation)))))
           (insert ";;; Generated autoloads from "
                   (autoload-trim-file-name file) "\n")
           ;; Warn if we put a line in loaddefs.el
@@ -325,9 +360,7 @@ are used."
           ;; Look for the section for LOAD-NAME.
           (while (and (not found)
                       (search-forward generate-autoload-section-header nil t))
-            (let ((form (condition-case ()
-                            (read (current-buffer))
-                          (end-of-file nil))))
+            (let ((form (autoload-read-section-header)))
               (cond ((string= (nth 2 form) load-name)
                      ;; We found the section for this file.
                      ;; Check if it is up to date.
@@ -394,7 +427,9 @@ Autoload section for %s is up to date."
                            (or existing-buffer
                                (kill-buffer (current-buffer))))))))
               (generate-file-autoloads file))))
-      (if (interactive-p) (save-buffer)))))
+      (and (interactive-p)
+           (buffer-modified-p)
+           (save-buffer)))))
 
 ;;;###autoload
 (defun update-autoloads-from-directories (&rest dirs)
@@ -420,9 +455,7 @@ This uses `update-file-autoloads' (which see) do its work."
       (save-excursion
         (goto-char (point-min))
         (while (search-forward generate-autoload-section-header nil t)
-          (let* ((form (condition-case ()
-                           (read (current-buffer))
-                         (end-of-file nil)))
+          (let* ((form (autoload-read-section-header))
                  (file (nth 3 form)))
             (cond ((not (stringp file)))
                   ((not (file-exists-p (expand-file-name file top-dir)))