Introduce scroll-bar-adjust-thumb-portion.

* xterm.c (scroll-bar-adjust-thumb-portion): New variable to
determine whether scroll bar thumb size should be adjusted or
not. Use variable for MOTIF.

* gtkutil.c (scroll-bar-adjust-thumb-portion): Use variable for
GTK.

1 files changed, 11 insertions, 7 deletions

diff --git a/src/gtkutil.c b/src/gtkutil.c
index 6daf189f74..af845f69e6 100644
--- a/src/gtkutil.c
+++ b/src/gtkutil.c
@@ -3795,13 +3795,17 @@ xg_set_toolkit_scroll_bar_thumb (struct scroll_bar *bar,
 
       adj = gtk_range_get_adjustment (GTK_RANGE (wscroll));
 
-      /* We do the same as for MOTIF in xterm.c, assume 30 chars per line
-         rather than the real portion value.  This makes the thumb less likely
-         to resize and that looks better.  */
-      portion = WINDOW_TOTAL_LINES (XWINDOW (bar->window)) * 30;
-      /* When the thumb is at the bottom, position == whole.
-         So we need to increase `whole' to make space for the thumb.  */
-      whole += portion;
+      if (scroll_bar_adjust_thumb_portion_p)
+        {
+          /* We do the same as for MOTIF in xterm.c, use 30 chars per
+             line rather than the real portion value.  This makes the
+             thumb less likely to resize and that looks better.  */
+          portion = WINDOW_TOTAL_LINES (XWINDOW (bar->window)) * 30;
+
+          /* When the thumb is at the bottom, position == whole.
+             So we need to increase `whole' to make space for the thumb.  */
+          whole += portion;
+        }
 
       if (whole <= 0)
         top = 0, shown = 1;