Fix horizontal scroll bar dragging in R2L paragraphs.

 src/w32term.c (w32_horizontal_scroll_bar_handle_click): Fix the
 second coordinate ('y') reported for dragging the horizontal
 scroll bar thumb.

2 files changed, 10 insertions, 1 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 0b9729d3833..871d7391c58 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2014-08-19  Eli Zaretskii  <eliz@gnu.org>
+
+        * w32term.c (w32_horizontal_scroll_bar_handle_click): Fix the
+        second coordinate ('y') reported for dragging the horizontal
+        scroll bar thumb.
+
 2014-08-19  YAMAMOTO Mitsuharu  <mituharu@math.s.chiba-u.ac.jp>
 
         * xdisp.c (erase_phys_cursor): Fix confusion between window-relative
diff --git a/src/w32term.c b/src/w32term.c
index 4eff5ab4cdd..2772dee6c02 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -4310,7 +4310,10 @@ w32_horizontal_scroll_bar_handle_click (struct scroll_bar *bar, W32Msg *msg,
       case SB_THUMBTRACK:
       case SB_THUMBPOSITION:
         if (HORIZONTAL_SCROLL_BAR_LEFT_RANGE (f, bar->width) <= 0xffff)
-          x = HIWORD (msg->msg.wParam);
+          {
+            x = HIWORD (msg->msg.wParam);
+            y = si.nMax - x - si.nPage;
+          }
         bar->dragging = 1;
         emacs_event->part = scroll_bar_horizontal_handle;