(indent-region): Rename arg ARG to COLUMN.

Don't add fill-prefix to empty line.
Don't change whitespace in empty line.

1 files changed, 21 insertions, 18 deletions

diff --git a/lisp/indent.el b/lisp/indent.el
index dd6a0588453..80c8d2d1efd 100644
--- a/lisp/indent.el
+++ b/lisp/indent.el
@@ -85,36 +85,39 @@ Called from a program, takes three arguments, START, END and ARG."
   "Function which is short cut to indent region using indent-according-to-mode.
 A value of nil means really run indent-according-to-mode on each line.")
 
-(defun indent-region (start end arg)
+(defun indent-region (start end column)
   "Indent each nonblank line in the region.
-With no argument, indent each line using indent-according-to-mode.
-\(If there is a fill prefix, make each line start with the fill prefix.)
+With no argument, indent each line using `indent-according-to-mode',
+or use `indent-region-function' to do the whole region if that's non-nil.
+If there is a fill prefix, make each line start with the fill prefix.
 With argument COLUMN, indent each line to that column.
 Called from a program, takes three args: START, END and COLUMN."
   (interactive "r\nP")
-  (if (null arg)
+  (if (null column)
       (if fill-prefix
           (save-excursion
             (goto-char end)
             (setq end (point-marker))
             (goto-char start)
             (let ((regexp (regexp-quote fill-prefix)))
-            (while (< (point) end)
-              (or (looking-at regexp)
-                  (insert fill-prefix))
-              (forward-line 1))))
+              (while (< (point) end)
+                (or (looking-at regexp)
+                    (and (bolp) (eolp))
+                    (insert fill-prefix))
+                (forward-line 1))))
         (if indent-region-function
             (funcall indent-region-function start end)
           (save-excursion
-          (goto-char end)
-          (setq end (point-marker))
-          (goto-char start)
-          (or (bolp) (forward-line 1))
-          (while (< (point) end)
-            (funcall indent-line-function)
-            (forward-line 1))
-          (move-marker end nil))))
-    (setq arg (prefix-numeric-value arg))
+            (goto-char end)
+            (setq end (point-marker))
+            (goto-char start)
+            (or (bolp) (forward-line 1))
+            (while (< (point) end)
+              (or (and (bolp) (eolp)))
+                  (funcall indent-line-function))
+              (forward-line 1))
+            (move-marker end nil))))
+    (setq column (prefix-numeric-value column))
     (save-excursion
       (goto-char end)
       (setq end (point-marker))
@@ -123,7 +126,7 @@ Called from a program, takes three args: START, END and COLUMN."
       (while (< (point) end)
         (delete-region (point) (progn (skip-chars-forward " \t") (point)))
         (or (eolp)
-        (indent-to arg 0))
+        (indent-to column 0))
         (forward-line 1))
       (move-marker end nil))))