(canonically-space-region): Doc fix.

(fill-region-as-paragraph): In adaptive-fill-mode,
if paragraph has one line, take the fill prefix from it.
(adaptive-fill-regexp): Doc fix.
(fill-individual-paragraphs): Use `adaptive-fill-regexp'
to determine `fill-prefix' if `adaptive-fill-mode' is non-nil.

1 files changed, 18 insertions, 14 deletions

diff --git a/lisp/textmodes/fill.el b/lisp/textmodes/fill.el
index 81791f0c506..a384125db90 100644
--- a/lisp/textmodes/fill.el
+++ b/lisp/textmodes/fill.el
@@ -61,7 +61,8 @@ reinserts the fill prefix in each resulting line."
   "*Regexp to match text at start of line that constitutes indentation.
 If Adaptive Fill mode is enabled, whatever text matches this pattern
 on the second line of a paragraph is used as the standard indentation
-for the paragraph.")
+for the paragraph.  If the paragraph has just one line, the indentation
+is taken from that line.")
 
 (defun current-fill-column ()
   "Return the fill-column to use for this line.
@@ -92,7 +93,7 @@ number equals or exceeds the local fill-column - right-margin difference."
 (defun canonically-space-region (beg end)
   "Remove extra spaces between words in region.
 Puts one space between words in region; two between sentences.
-Remove indenation from each line."
+Remove indentation from each line."
   (interactive "r")
   (save-excursion
     (goto-char beg)
@@ -180,17 +181,17 @@ space does not end a sentence, so don't break a line there."
           (save-excursion
             (goto-char from)
             (if (eolp) (forward-line 1))
-            (forward-line 1)
+            ;; Move to the second line unless there is just one.
+            (let ((firstline (point)))
+              (forward-line 1)
+              (if (>= (point) to)
+                  (goto-char firstline)))
             (move-to-left-margin)
-            (if (< (point) to)
-                (let ((start (point)))
-                  (re-search-forward adaptive-fill-regexp)
-                  (setq fill-prefix (buffer-substring start (point)))
-                  (set-text-properties 0 (length fill-prefix) nil
-                                       fill-prefix)))
-            ;; If paragraph has only one line, don't assume in general
-            ;; that additional lines would have the same starting
-            ;; decoration.  Assume no indentation.
+            (let ((start (point)))
+              (re-search-forward adaptive-fill-regexp)
+              (setq fill-prefix (buffer-substring start (point)))
+              (set-text-properties 0 (length fill-prefix) nil
+                                   fill-prefix))
             ))
 
       (save-restriction
@@ -762,8 +763,11 @@ MAIL-FLAG for a mail message, i. e. don't fill header lines."
                    (if (not (and fill-prefix
                                  (looking-at fill-prefix-regexp)))
                        (setq fill-prefix
-                             (buffer-substring (point)
-                                               (save-excursion (skip-chars-forward " \t") (point)))
+                             (if (and adaptive-fill-mode adaptive-fill-regexp
+                                      (looking-at (concat "\\(" adaptive-fill-regexp "\\)")))
+                                 (match-string 1)
+                               (buffer-substring (point)
+                                                 (save-excursion (skip-chars-forward " \t") (point))))
                              fill-prefix-regexp
                              (regexp-quote fill-prefix)))
                    (forward-line 1)