1 files changed, 25 insertions, 17 deletions

diff --git a/src/bidi.c b/src/bidi.c
index 6f3d749ef22..c6bea62f67b 100644
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -1,6 +1,6 @@
 /* Low-level bidirectional buffer/string-scanning functions for GNU Emacs.
-   Copyright (C) 2000-2001, 2004-2005, 2009-2012
-   Free Software Foundation, Inc.
+   Copyright (C) 2000-2001, 2004-2005, 2009-2013 Free Software
+   Foundation, Inc.
 
 This file is part of GNU Emacs.
 
@@ -910,7 +910,7 @@ bidi_char_at_pos (ptrdiff_t bytepos, const unsigned char *s, bool unibyte)
   return STRING_CHAR (s);
 }
 
-/* Fetch and return the character at BYTEPOS/CHARPOS.  If that
+/* Fetch and return the character at CHARPOS/BYTEPOS.  If that
    character is covered by a display string, treat the entire run of
    covered characters as a single character, either u+2029 or u+FFFC,
    and return their combined length in CH_LEN and NCHARS.  DISP_POS
@@ -925,7 +925,7 @@ bidi_char_at_pos (ptrdiff_t bytepos, const unsigned char *s, bool unibyte)
    string to iterate, or NULL if iterating over a buffer or a Lisp
    string; in the latter case, STRING->lstring is the Lisp string.  */
 static int
-bidi_fetch_char (ptrdiff_t bytepos, ptrdiff_t charpos, ptrdiff_t *disp_pos,
+bidi_fetch_char (ptrdiff_t charpos, ptrdiff_t bytepos, ptrdiff_t *disp_pos,
                  int *disp_prop, struct bidi_string_data *string,
                  bool frame_window_p, ptrdiff_t *ch_len, ptrdiff_t *nchars)
 {
@@ -1109,8 +1109,8 @@ bidi_find_paragraph_start (ptrdiff_t pos, ptrdiff_t pos_byte)
          display string?  And what if a display string covering some
          of the text over which we scan back includes
          paragraph_start_re?  */
-      pos = find_next_newline_no_quit (pos - 1, -1);
-      pos_byte = CHAR_TO_BYTE (pos);
+      DEC_BOTH (pos, pos_byte);
+      pos = find_newline_no_quit (pos, pos_byte, -1, &pos_byte);
     }
   if (n >= MAX_PARAGRAPH_SEARCH)
     pos_byte = BEGV_BYTE;
@@ -1223,7 +1223,7 @@ bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it, bool no_default_p)
         bytepos = pstartbyte;
         if (!string_p)
           pos = BYTE_TO_CHAR (bytepos);
-        ch = bidi_fetch_char (bytepos, pos, &disp_pos, &disp_prop,
+        ch = bidi_fetch_char (pos, bytepos, &disp_pos, &disp_prop,
                               &bidi_it->string,
                               bidi_it->frame_window_p, &ch_len, &nchars);
         type = bidi_get_type (ch, NEUTRAL_DIR);
@@ -1251,7 +1251,7 @@ bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it, bool no_default_p)
                 && bidi_at_paragraph_end (pos, bytepos) >= -1)
               break;
             /* Fetch next character and advance to get past it.  */
-            ch = bidi_fetch_char (bytepos, pos, &disp_pos,
+            ch = bidi_fetch_char (pos, bytepos, &disp_pos,
                                   &disp_prop, &bidi_it->string,
                                   bidi_it->frame_window_p, &ch_len, &nchars);
             pos += nchars;
@@ -1282,8 +1282,7 @@ bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it, bool no_default_p)
                     /* FXIME: What if p is covered by a display
                        string?  See also a FIXME inside
                        bidi_find_paragraph_start.  */
-                    p--;
-                    pbyte = CHAR_TO_BYTE (p);
+                    DEC_BOTH (p, pbyte);
                     prevpbyte = bidi_find_paragraph_start (p, pbyte);
                   }
                 pstartbyte = prevpbyte;
@@ -1356,15 +1355,19 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
                : bidi_it->string.s);
 
           if (bidi_it->charpos < 0)
-            bidi_it->charpos = 0;
-          bidi_it->bytepos = bidi_count_bytes (p, 0, 0, bidi_it->charpos,
-                                               bidi_it->string.unibyte);
+            bidi_it->charpos = bidi_it->bytepos = 0;
+          eassert (bidi_it->bytepos == bidi_count_bytes (p, 0, 0,
+                                                         bidi_it->charpos,
+                                                         bidi_it->string.unibyte));
         }
       else
         {
           if (bidi_it->charpos < BEGV)
-            bidi_it->charpos = BEGV;
-          bidi_it->bytepos = CHAR_TO_BYTE (bidi_it->charpos);
+            {
+              bidi_it->charpos = BEGV;
+              bidi_it->bytepos = BEGV_BYTE;
+            }
+          eassert (bidi_it->bytepos == CHAR_TO_BYTE (bidi_it->charpos));
         }
     }
   /* Don't move at end of buffer/string.  */
@@ -1397,7 +1400,7 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
       /* Fetch the character at BYTEPOS.  If it is covered by a
          display string, treat the entire run of covered characters as
          a single character u+FFFC.  */
-      curchar = bidi_fetch_char (bidi_it->bytepos, bidi_it->charpos,
+      curchar = bidi_fetch_char (bidi_it->charpos, bidi_it->bytepos,
                                  &bidi_it->disp_pos, &bidi_it->disp_prop,
                                  &bidi_it->string, bidi_it->frame_window_p,
                                  &bidi_it->ch_len, &bidi_it->nchars);
@@ -1973,6 +1976,7 @@ bidi_resolve_neutral (struct bidi_it *bidi_it)
                 next_type = STRONG_R;
                 break;
               case WEAK_BN:
+              case NEUTRAL_ON:  /* W6/Retaining */
                 if (!bidi_explicit_dir_char (bidi_it->ch))
                   emacs_abort (); /* can't happen: BNs are skipped */
                 /* FALLTHROUGH */
@@ -2189,7 +2193,7 @@ bidi_level_of_next_char (struct bidi_it *bidi_it)
       if (bidi_it->nchars <= 0)
         emacs_abort ();
       do {
-        ch = bidi_fetch_char (bpos += clen, cpos += nc, &disp_pos, &dpp, &bs,
+        ch = bidi_fetch_char (cpos += nc, bpos += clen, &disp_pos, &dpp, &bs,
                               fwp, &clen, &nc);
         if (ch == '\n' || ch == BIDI_EOB)
           chtype = NEUTRAL_B;
@@ -2391,6 +2395,10 @@ bidi_move_to_visually_next (struct bidi_it *bidi_it)
       next_level = bidi_peek_at_next_level (bidi_it);
       while (next_level != expected_next_level)
         {
+          /* If next_level is -1, it means we have an unresolved level
+             in the cache, which at this point should not happen.  If
+             it does, we will infloop.  */
+          eassert (next_level >= 0);
           expected_next_level += incr;
           level_to_search += incr;
           bidi_find_other_level_edge (bidi_it, level_to_search, !ascending);