Improve scrolling when line-spacing is non-nil.

 lisp/simple.el (line-move-partial, line-move): Account for
 line-spacing.

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index c34cab68426665c8aea53e99cd3b278d8b51fe33..a04079ced2469e58e501b18aba12dcf4c04ea37c 100644 (file)
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2013-07-08  Eli Zaretskii  <eliz@gnu.org>
+
+       * simple.el (line-move-partial, line-move): Account for
+       line-spacing.
+
 2013-07-08  Lars Magne Ingebrigtsen  <larsi@gnus.org>
 
        * net/shr.el (shr-map): Reinstate the `u' key binding, since it's

diff --git a/lisp/simple.el b/lisp/simple.el
index 69c3926f09130eb521885ab022bd0d0254eca29b..1baf0eb6d4e4eaf244846df42248f78efb9edc53 100644 (file)
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -4764,15 +4764,27 @@ The value is a floating-point number."
           (this-height (nth 0 this-lh))
           (this-ypos (nth 2 this-lh))
           (dfh (default-font-height))
-          py vs)
+          (lsp (if (display-graphic-p)
+                   (or line-spacing
+                       (default-value 'line-spacing)
+                       (frame-parameter nil 'line-spacing)
+                       0)
+                 0))
+          py vs rowh dlh)
+      (if (floatp lsp)
+         (setq lsp (* dfh lsp)))
+      ;; Default height of a text line, accounting for the default
+      ;; face's font and line-spacing, if any.
+      (setq dlh (+ dfh lsp))
       (when (or (null lh)
-               (>= rbot dfh)
-               (<= ypos (- dfh))
+               (>= rbot dlh)
+               (<= ypos (- dlh))
                (null this-lh)
-               (<= this-ypos (- dfh)))
+               (<= this-ypos (- dlh)))
        (unless lh
          (let ((wend (pos-visible-in-window-p t nil t)))
            (setq rbot (nth 3 wend)
+                 rowh  (nth 4 wend)
                  vpos (nth 5 wend))))
        (unless this-lh
          (let ((wstart (pos-visible-in-window-p nil nil t)))
@@ -4789,14 +4801,14 @@ The value is a floating-point number."
        (cond
         ;; If last line of window is fully visible, and vscrolling
         ;; more would make this line invisible, move forward.
-        ((and (or (< (setq vs (window-vscroll nil t)) dfh)
+        ((and (or (< (setq vs (window-vscroll nil t)) dlh)
                   (null this-height)
-                  (<= this-height dfh))
+                  (<= this-height dlh))
               (or (null rbot) (= rbot 0)))
          nil)
         ;; If cursor is not in the bottom scroll margin, and the
         ;; current line is is not too tall, move forward.
-        ((and (or (null this-height) (<= this-height dfh))
+        ((and (or (null this-height) (<= this-height dlh))
               vpos
               (> vpos 0)
               (< py
@@ -4806,15 +4818,26 @@ The value is a floating-point number."
         ;; or clear vscroll and move forward at end of tall image.
         ((> vs 0)
          (when (or (and rbot (> rbot 0))
-                   (and this-height (> this-height dfh)))
-           (set-window-vscroll nil (+ vs dfh) t)))
+                   (and this-height (> this-height dlh)))
+           (set-window-vscroll nil (+ vs dlh) t)))
         ;; If cursor just entered the bottom scroll margin, move forward,
-        ;; but also vscroll one line so redisplay won't recenter.
+        ;; but also optionally vscroll one line so redisplay won't recenter.
         ((and vpos
               (> vpos 0)
               (= py (min (- (window-screen-lines) scroll-margin 1)
                          (1- vpos))))
-         (set-window-vscroll nil dfh t)
+         ;; Don't vscroll if the partially-visible line at window
+         ;; bottom has the default height (a.k.a. "just one more text
+         ;; line"): in that case, we do want redisplay to behave
+         ;; normally, i.e. recenter or whatever.
+         ;;
+         ;; Note: ROWH + RBOT from the value returned by
+         ;; pos-visible-in-window-p give the total height of the
+         ;; partially-visible glyph row at the end of the window.  As
+         ;; we are dealing with floats, we disregard sub-pixel
+         ;; discrepancies between that and DLH.
+         (if (and rowh rbot (>= (- (+ rowh rbot) dlh) 1))
+             (set-window-vscroll nil dlh t))
          (line-move-1 arg noerror to-end)
          t)
         ;; If there are lines above the last line, scroll-up one line.
@@ -4823,7 +4846,7 @@ The value is a floating-point number."
          t)
         ;; Finally, start vscroll.
         (t
-         (set-window-vscroll nil dfh t)))))))
+         (set-window-vscroll nil dlh t)))))))
 
 
 ;; This is like line-move-1 except that it also performs
@@ -4857,13 +4880,25 @@ The value is a floating-point number."
            ;; If we moved into a tall line, set vscroll to make
            ;; scrolling through tall images more smooth.
            (let ((lh (line-pixel-height))
-                 (dfh (default-font-height)))
+                 (dfh (default-font-height))
+                 (lsp (if (display-graphic-p)
+                          (or line-spacing
+                              (default-value 'line-spacing)
+                              (frame-parameter nil 'line-spacing)
+                              0)
+                        0))
+                 dlh)
+             ;; DLH is the default height of a text line, accounting
+             ;; for the default face's font and line-spacing, if any.
+             (if (floatp lsp)
+                 (setq lsp (* dfh lsp)))
+             (setq dlh (+ dfh lsp))
              (if (and (< arg 0)
                       (< (point) (window-start))
-                      (> lh dfh))
+                      (> lh dlh))
                  (set-window-vscroll
                   nil
-                  (- lh dfh) t))))
+                  (- lh dlh) t))))
        (line-move-1 arg noerror to-end)))))
 
 ;; Display-based alternative to line-move-1.