Fix rare aborts in bidi.c.

 src/bidi.c (bidi_resolve_neutral): After finding the next
 non-neutral character, accept NEUTRAL_ON type as well, because
 directional control characters, such as LRE and RLE, have their
 type converted to that by bidi_resolve_weak.  This avoids aborts
 when LRE/RLE follows a run of neutrals.
 (bidi_move_to_visually_next): Assert that return value of
 bidi_peek_at_next_level is non-negative.  Negative values will
 cause an infloop.

diff --git a/src/ChangeLog b/src/ChangeLog
index e33d2fa..b5a1e0d 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,14 @@
+2013-02-11  Eli Zaretskii  <eliz@gnu.org>
+
+       * bidi.c (bidi_resolve_neutral): After finding the next
+       non-neutral character, accept NEUTRAL_ON type as well, because
+       directional control characters, such as LRE and RLE, have their
+       type converted to that by bidi_resolve_weak.  This avoids aborts
+       when LRE/RLE follows a run of neutrals.
+       (bidi_move_to_visually_next): Assert that return value of
+       bidi_peek_at_next_level is non-negative.  Negative values will
+       cause an infloop.
+
 2013-02-05  Daniel Colascione  <dancol@dancol.org>
 
        * emacs.c: Use execvp, not execv, when DAEMON_MUST_EXEC, so that

diff --git a/src/bidi.c b/src/bidi.c
index b067c81..db2e48a 100644 (file)
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -1973,6 +1973,7 @@ 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 */
@@ -2391,6 +2392,10 @@ 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);