(fill-context-prefix): Fix criteria for first line,

and for second line; always fetch prefixes from both lines.

diff --git a/lisp/textmodes/fill.el b/lisp/textmodes/fill.el
index c3628be99f88ef1f4c3896e46bb1646cf261b835..a769bd33616edc43ac4c382805c21d1f8b6dcefe 100644 (file)
--- a/lisp/textmodes/fill.el
+++ b/lisp/textmodes/fill.el
@@ -1,6 +1,6 @@
 ;;; fill.el --- fill commands for Emacs
 
-;; Copyright (C) 1985, 86, 92, 94, 95, 1996 Free Software Foundation, Inc.
+;; Copyright (C) 1985, 86, 92, 94, 95, 96, 1997 Free Software Foundation, Inc.
 
 ;; Keywords: wp
 
@@ -183,45 +183,60 @@ act as a paragraph-separator."
     (if (eolp) (forward-line 1))
     ;; Move to the second line unless there is just one.
     (let ((firstline (point))
+         first-line-prefix
          ;; Non-nil if we are on the second line.
          at-second
-         result)
+         second-line-prefix
+         start)
+      (move-to-left-margin)
+      (setq start (point))
+      (setq first-line-prefix
+           (cond ((looking-at paragraph-start) nil)
+                 ((and adaptive-fill-regexp (looking-at adaptive-fill-regexp))
+                  (buffer-substring-no-properties start (match-end 0)))
+                 (adaptive-fill-function (funcall adaptive-fill-function))))
       (forward-line 1)
       (if (>= (point) to)
          (goto-char firstline)
-       (setq at-second t))
-      (move-to-left-margin)
-      (let ((start (point)))
-       (setq result
-             (if (not (looking-at paragraph-start))
-                 (cond ((and adaptive-fill-regexp (looking-at adaptive-fill-regexp))
-                        (buffer-substring-no-properties start (match-end 0)))
-                       (adaptive-fill-function (funcall adaptive-fill-function)))))
-       (if at-second
-           ;; If we get a fill prefix from the second line,
-           ;; make sure it's on the first line too.
-           (and result
-                (save-excursion
-                  (forward-line -1)
-                  (if (looking-at (regexp-quote result))
-                      result)))
-         ;; If we get a fill prefix from a one-line paragraph,
-         ;; maybe change it to whitespace,
-         ;; and check that it isn't a paragraph starter.
-         (if result
-             (progn
-               ;; If RESULT comes from the first line,
-               ;; see if it seems reasonable to use for all lines.
-               ;; If not, replace it with whitespace.
-               (or (and first-line-regexp
-                        (string-match first-line-regexp result))
-                   (and comment-start-skip
-                        (string-match comment-start-skip result))
-                   (setq result (make-string (string-width result) ?\ )))
-               ;; But either way, reject it if it indicates
-               ;; the start of a paragraph.
-               (if (not (eq 0 (string-match paragraph-start result)))
-                   result))))))))
+       (setq at-second t)
+       (move-to-left-margin)
+       (setq start (point))
+       (setq second-line-prefix
+             (cond ((looking-at paragraph-start) nil)
+                   ((and adaptive-fill-regexp (looking-at adaptive-fill-regexp))
+                    (buffer-substring-no-properties start (match-end 0)))
+                   (adaptive-fill-function (funcall adaptive-fill-function)))))
+      (if at-second
+         ;; If we get a fill prefix from the second line,
+         ;; make sure it or something compatible is on the first line too.
+         (and second-line-prefix
+              (if (or (string-match (regexp-quote second-line-prefix)
+                                    first-line-prefix)
+                      (and (string-match "[ \t]" second-line-prefix)
+                           (>= (string-width first-line-prefix)
+                               (string-width second-line-prefix))))
+                    second-line-prefix))
+       ;; If we get a fill prefix from a one-line paragraph,
+       ;; maybe change it to whitespace,
+       ;; and check that it isn't a paragraph starter.
+       (if first-line-prefix
+           (let ((result
+                  ;; If first-line-prefix comes from the first line,
+                  ;; see if it seems reasonable to use for all lines.
+                  ;; If not, replace it with whitespace.
+                  (if (or (and first-line-regexp
+                               (string-match first-line-regexp
+                                             first-line-prefix))
+                          (and comment-start-skip
+                               (string-match comment-start-skip
+                                             first-line-prefix)))
+                      first-line-prefix
+                    (make-string (string-width first-line-prefix) ?\ ))))
+             ;; But either way, reject it if it indicates the start
+             ;; of a paragraph when text follows it.
+             (if (not (eq 0 (string-match paragraph-start
+                                          (concat result "a"))))
+                 result))))))))
 
 (defun fill-region-as-paragraph (from to &optional justify
                                      nosqueeze squeeze-after)