* xdisp.c (redisplay_window): Make the scrollbar reflect the

	extent of the visible region, not the whole buffer.

diff --git a/src/xdisp.c b/src/xdisp.c
index ba33e111387fcdef5cfeb0bd13898f91b3e2305b..562e10aafbd81350245054103b0181856e751fcb 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -1060,6 +1060,11 @@ done:
       int start, end, whole;
 
       /* Calculate the start and end positions for the current window.
+        At some point, it would be nice to choose between scrollbars
+        which reflect the whole buffer size, with special markers
+        indicating narrowing, and scrollbars which reflect only the
+        visible region.
+
         Note that minibuffers sometimes aren't displaying any text.  */
       if (! MINI_WINDOW_P (w)
          || (w == XWINDOW (minibuf_window) && ! echo_area_glyphs))
@@ -1068,7 +1073,10 @@ done:
          /* I don't think this is guaranteed to be right.  For the
             moment, we'll pretend it is.  */
          end = Z - XINT (w->window_end_pos);
-         whole = Z - BEG;
+         whole = ZV - BEGV;
+
+         if (end < start) end = start;
+         if (whole > (end - start)) whole = end - start;
        }
       else
        start = end = whole = 0;