Fix cursor positioning in rows completely covered by display strings.

 src/xdisp.c (set_cursor_from_row): If `cursor' property on a display
 string comes from a `display' text property, use the buffer
 position of that property as if we actually saw that position in
 the row's glyphs.

2 files changed, 36 insertions, 5 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index cbf9abd0ea1..189a7e4e775 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2012-03-31  Eli Zaretskii  <eliz@gnu.org>
+
+        * xdisp.c (set_cursor_from_row): If `cursor' property on a display
+        string comes from a `display' text property, use the buffer
+        position of that property as if we actually saw that position in
+        the row's glyphs.
+
 2012-03-30  Eli Zaretskii  <eliz@gnu.org>
 
         * xdisp.c (append_space_for_newline): If the default face was
diff --git a/src/xdisp.c b/src/xdisp.c
index 118480a20ae..302a09dd974 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -13800,16 +13800,31 @@ set_cursor_from_row (struct window *w, struct glyph_row *row,
 
             chprop = Fget_char_property (make_number (glyph_pos), Qcursor,
                                          glyph->object);
+            if (!NILP (chprop))
+              {
+                /* If the string came from a `display' text property,
+                   look up the buffer position of that property and
+                   use that position to update bpos_max, as if we
+                   actually saw such a position in one of the row's
+                   glyphs.  This helps with supporting integer values
+                   of `cursor' property on the display string in
+                   situations where most or all of the row's buffer
+                   text is completely covered by display properties,
+                   so that no glyph with valid buffer positions is
+                   ever seen in the row.  */
+                EMACS_INT prop_pos =
+                  string_buffer_position_lim (glyph->object, pos_before,
+                                              pos_after, 0);
+
+                if (prop_pos >= pos_before)
+                  bpos_max = prop_pos - 1;
+              }
             if (INTEGERP (chprop))
               {
                 bpos_covered = bpos_max + XINT (chprop);
                 /* If the `cursor' property covers buffer positions up
                    to and including point, we should display cursor on
-                   this glyph.  Note that overlays and text properties
-                   with string values stop bidi reordering, so every
-                   buffer position to the left of the string is always
-                   smaller than any position to the right of the
-                   string.  Therefore, if a `cursor' property on one
+                   this glyph.  Note that, if a `cursor' property on one
                    of the string's characters has an integer value, we
                    will break out of the loop below _before_ we get to
                    the position match above.  IOW, integer values of
@@ -13869,6 +13884,15 @@ set_cursor_from_row (struct window *w, struct glyph_row *row,
 
             chprop = Fget_char_property (make_number (glyph_pos), Qcursor,
                                          glyph->object);
+            if (!NILP (chprop))
+              {
+                EMACS_INT prop_pos =
+                  string_buffer_position_lim (glyph->object, pos_before,
+                                              pos_after, 0);
+
+                if (prop_pos >= pos_before)
+                  bpos_max = prop_pos - 1;
+              }
             if (INTEGERP (chprop))
               {
                 bpos_covered = bpos_max + XINT (chprop);