Started work on string reordering. Just compiled, not yet tested.

 src/bidi.c (bidi_paragraph_info): Delete unused struct.
 (bidi_cache_idx, bidi_cache_last_idx): Declare EMACS_INT.
 (bidi_cache_start): New variable.
 (bidi_cache_reset): Reset bidi_cache_idx to bidi_cache_start, not
 to zero.
 (bidi_cache_fetch_state, bidi_cache_search)
 (bidi_cache_find_level_change, bidi_cache_iterator_state)
 (bidi_cache_find, bidi_peek_at_next_level)
 (bidi_level_of_next_char, bidi_find_other_level_edge)
 (bidi_move_to_visually_next): Compare cache index with
 bidi_cache_start rather than with zero.
 (bidi_fetch_char): Accept new argument STRING; all callers
 changed.  Support iteration over a string.
 (bidi_paragraph_init, bidi_resolve_explicit_1)
 (bidi_resolve_explicit, bidi_resolve_weak)
 (bidi_level_of_next_char, bidi_move_to_visually_next): Support
 iteration over a string.
 (bidi_set_sor_type, bidi_resolve_explicit_1)
 (bidi_resolve_explicit, bidi_type_of_next_char): ignore_bn_limit
 can now be zero (for strings); special values 0 and -1 were
 changed to -1 and -2, respectively.
 (bidi_char_at_pos): New function.
 (bidi_paragraph_init, bidi_resolve_explicit, bidi_resolve_weak):
 Call it instead of FETCH_MULTIBYTE_CHAR.
 (bidi_move_to_visually_next): Abort if charpos or bytepos were not
 initialized to valid values.
 (bidi_init_it): Don't initialize charpos and bytepos with invalid
 values.
 src/xdisp.c (compute_display_string_pos)
 (compute_display_string_end): Accept additional argument STRING.
 (init_iterator, reseat_1): Initialize bidi_it->string.s to NULL.
 (reseat_to_string): Initialize bidi_it->string.s and
 bidi_it->string.schars.
 src/dispextern.h (struct bidi_string_data): New structure.
 (struct bidi_it): New member `string'.  Make flag members be 1-bit
 fields, and put them last in the struct.
 (compute_display_string_pos, compute_display_string_end): Update
 prototypes.

1 files changed, 18 insertions, 6 deletions

diff --git a/src/dispextern.h b/src/dispextern.h
index 7138c2225e..0f7089d791 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -1812,9 +1812,18 @@ struct bidi_stack {
   bidi_dir_t override;
 };
 
+/* Data type for storing information about a string being iterated on.  */
+struct bidi_string_data {
+  const unsigned char *s;	/* the string, or NULL if reordering buffer */
+  EMACS_INT schars;		/* the number of characters in the string,
+				   excluding the terminating null */
+  unsigned from_disp_str : 1;	/* 1 means the string comes from a
+				   display property */
+};
+
 /* Data type for reordering bidirectional text.  */
 struct bidi_it {
-  EMACS_INT bytepos;		/* iterator's position in buffer */
+  EMACS_INT bytepos;		/* iterator's position in buffer/string */
   EMACS_INT charpos;
   int ch;			/* character at that position, or u+FFFC
 				   ("object replacement character") for a run
@@ -1844,12 +1853,13 @@ struct bidi_it {
      iterator state is saved, pushed, or popped.  So only put here
      stuff that is not part of the bidi iterator's state!  */
   struct bidi_stack level_stack[BIDI_MAXLEVEL]; /* stack of embedding levels */
-  int first_elt;		/* if non-zero, examine current char first */
+  struct bidi_string_data string;	/* string to reorder */
   bidi_dir_t paragraph_dir;	/* current paragraph direction */
-  int new_paragraph;		/* if non-zero, we expect a new paragraph */
-  int frame_window_p;		/* non-zero if displaying on a GUI frame */
   EMACS_INT separator_limit;	/* where paragraph separator should end */
   EMACS_INT disp_pos;		/* position of display string after ch */
+  unsigned first_elt : 1;	/* if non-zero, examine current char first */
+  unsigned new_paragraph : 1;	/* if non-zero, we expect a new paragraph */
+  unsigned frame_window_p : 1;	/* non-zero if displaying on a GUI frame */
 };
 
 /* Value is non-zero when the bidi iterator is at base paragraph
@@ -3007,8 +3017,10 @@ extern void reseat_at_previous_visible_line_start (struct it *);
 extern Lisp_Object lookup_glyphless_char_display (int, struct it *);
 extern int calc_pixel_width_or_height (double *, struct it *, Lisp_Object,
                                        struct font *, int, int *);
-extern EMACS_INT compute_display_string_pos (EMACS_INT, int);
-extern EMACS_INT compute_display_string_end (EMACS_INT);
+extern EMACS_INT compute_display_string_pos (EMACS_INT,
+					     struct bidi_string_data *, int);
+extern EMACS_INT compute_display_string_end (EMACS_INT,
+					     struct bidi_string_data *);
 
 #ifdef HAVE_WINDOW_SYSTEM