Fix cursor motion with long continued lines near window bottom.

 src/xdisp.c (try_cursor_movement): Check for the need to scroll more
 accurately, and prefer exact match for point under bidi.

2 files changed, 27 insertions, 5 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index b2f2334427c..1176c9254ea 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -7,6 +7,8 @@
         (handle_single_display_spec): If the display spec is of the form
         `(space ...)', and specifies display in the text area, return 2
         rather than 1.
+        (try_cursor_movement): Check for the need to scroll more
+        accurately, and prefer exact match for point under bidi.
 
         * dispextern.h (struct bidi_it): Rename the disp_prop_p member
         into disp_prop; all users changed.
diff --git a/src/xdisp.c b/src/xdisp.c
index 5cbc7747f2f..55bbb7cf62e 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -14593,15 +14593,33 @@ try_cursor_movement (Lisp_Object window, struct text_pos startp, int *scroll_ste
 
               do
                 {
+                  int at_zv_p = 0, exact_match_p = 0;
+
                   if (MATRIX_ROW_START_CHARPOS (row) <= PT
                       && PT <= MATRIX_ROW_END_CHARPOS (row)
                       && cursor_row_p (row))
                     rv |= set_cursor_from_row (w, row, w->current_matrix,
                                                0, 0, 0, 0);
-                  /* As soon as we've found the first suitable row
-                     whose ends_at_zv_p flag is set, we are done.  */
-                  if (rv
-                      && MATRIX_ROW (w->current_matrix, w->cursor.vpos)->ends_at_zv_p)
+                  /* As soon as we've found the exact match for point,
+                     or the first suitable row whose ends_at_zv_p flag
+                     is set, we are done.  */
+                  at_zv_p =
+                    MATRIX_ROW (w->current_matrix, w->cursor.vpos)->ends_at_zv_p;
+                  if (!at_zv_p)
+                    {
+                      struct glyph_row *candidate =
+                        MATRIX_ROW (w->current_matrix, w->cursor.vpos);
+                      struct glyph *g =
+                        candidate->glyphs[TEXT_AREA] + w->cursor.hpos;
+                      EMACS_INT endpos = MATRIX_ROW_END_CHARPOS (candidate);
+
+                      exact_match_p =
+                        (BUFFERP (g->object) && g->charpos == PT)
+                        || (INTEGERP (g->object)
+                            && (g->charpos == PT
+                                || (g->charpos == 0 && endpos - 1 == PT)));
+                    }
+                  if (rv && (at_zv_p || exact_match_p))
                     {
                       rc = CURSOR_MOVEMENT_SUCCESS;
                       break;
@@ -14617,7 +14635,9 @@ try_cursor_movement (Lisp_Object window, struct text_pos startp, int *scroll_ste
                  loop before all the candidates were examined, signal
                  to the caller that this method failed.  */
               if (rc != CURSOR_MOVEMENT_SUCCESS
-                  && (!rv || MATRIX_ROW_CONTINUATION_LINE_P (row)))
+                  && !(rv
+                       && !MATRIX_ROW_CONTINUATION_LINE_P (row)
+                       && !row->continued_p))
                 rc = CURSOR_MOVEMENT_MUST_SCROLL;
               else if (rv)
                 rc = CURSOR_MOVEMENT_SUCCESS;