Fix parts 1 & 2 of bug #10183 with RTL headings in Org mode.

 src/xdisp.c (handle_invisible_prop): If the invisible text ends just
 before a newline, prepare the bidi iterator for consuming the
 newline, and keep the current paragraph direction.

diff --git a/src/ChangeLog b/src/ChangeLog
index ed47da2caa1109bcef415ec43caa4ca6fcbc96bf..efba68d99d6deedffffa9216f18f3d07737332a5 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2011-12-03  Eli Zaretskii  <eliz@gnu.org>
+
+       * xdisp.c (handle_invisible_prop): If the invisible text ends just
+       before a newline, prepare the bidi iterator for consuming the
+       newline, and keep the current paragraph direction.  (Bug#10183)
+
 2011-12-02  Juri Linkov  <juri@jurta.org>
 
        * search.c (Fword_search_regexp): New Lisp function created from

diff --git a/src/xdisp.c b/src/xdisp.c
index c9b9b5c5e88e5e7cb6b993f30e533fb69f258c31..b9741d97d30c78b92cc3a67ce2e46501ef0a8b1d 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -4093,26 +4093,37 @@ handle_invisible_prop (struct it *it)
          if (it->bidi_p && newpos < ZV)
            {
              EMACS_INT bpos = CHAR_TO_BYTE (newpos);
-
-             if (FETCH_BYTE (bpos) == '\n'
-                 || (newpos > BEGV && FETCH_BYTE (bpos - 1) == '\n'))
+             int on_newline = FETCH_BYTE (bpos) == '\n';
+             int after_newline =
+               newpos <= BEGV || FETCH_BYTE (bpos - 1) == '\n';
+
+             /* If the invisible text ends on a newline or on a
+                character after a newline, we can avoid the costly,
+                character by character, bidi iteration to NEWPOS, and
+                instead simply reseat the iterator there.  That's
+                because all bidi reordering information is tossed at
+                the newline.  This is a big win for modes that hide
+                complete lines, like Outline, Org, etc.  */
+             if (on_newline || after_newline)
                {
-                 /* If the invisible text ends on a newline or the
-                    character after a newline, we can avoid the
-                    costly, character by character, bidi iteration to
-                    newpos, and instead simply reseat the iterator
-                    there.  That's because all bidi reordering
-                    information is tossed at the newline.  This is a
-                    big win for modes that hide complete lines, like
-                    Outline, Org, etc.  (Implementation note: the
-                    call to reseat_1 is necessary, because it signals
-                    to the bidi iterator that it needs to reinit its
-                    internal information when the next element for
-                    display is requested.  */
                  struct text_pos tpos;
+                 bidi_dir_t pdir = it->bidi_it.paragraph_dir;
 
                  SET_TEXT_POS (tpos, newpos, bpos);
                  reseat_1 (it, tpos, 0);
+                 /* If we reseat on a newline, we need to prep the
+                    bidi iterator for advancing to the next character
+                    after the newline, keeping the current paragraph
+                    direction (so that PRODUCE_GLYPHS does TRT wrt
+                    prepending/appending glyphs to a glyph row).  */
+                 if (on_newline)
+                   {
+                     it->bidi_it.first_elt = 0;
+                     it->bidi_it.paragraph_dir = pdir;
+                     it->bidi_it.ch = '\n';
+                     it->bidi_it.nchars = 1;
+                     it->bidi_it.ch_len = 1;
+                   }
                }
              else      /* Must use the slow method.  */
                {
@@ -4121,11 +4132,11 @@ handle_invisible_prop (struct it *it)
                     non-base embedding level.  Therefore, we need to
                     skip invisible text using the bidi iterator,
                     starting at IT's current position, until we find
-                    ourselves outside the invisible text.  Skipping
-                    invisible text _after_ bidi iteration avoids
-                    affecting the visual order of the displayed text
-                    when invisible properties are added or
-                    removed.  */
+                    ourselves outside of the invisible text.
+                    Skipping invisible text _after_ bidi iteration
+                    avoids affecting the visual order of the
+                    displayed text when invisible properties are
+                    added or removed.  */
                  if (it->bidi_it.first_elt && it->bidi_it.charpos < ZV)
                    {
                      /* If we were `reseat'ed to a new paragraph,