master 5e8fbf7789: Clean up implementation of N0 per UAX#9

[Eli Zaretskii]

branch: master
commit 5e8fbf7789613511061d78a42ca7f91bc831f786
Author: Eli Zaretskii <eliz@gnu.org>
Commit: Eli Zaretskii <eliz@gnu.org>

    Clean up implementation of N0 per UAX#9
    
    * src/bidi.c (bidi_resolve_brackets): Instead of requiring
    prev_for_neutral's type to be known, fall back on SOS, per
    the UBA.
---
 src/bidi.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/bidi.c b/src/bidi.c
index 44b7422bdc..4d2c74b17c 100644
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -2927,8 +2927,11 @@ bidi_resolve_brackets (struct bidi_it *bidi_it)
       else if (bidi_it->bracket_enclosed_type == STRONG_L   /* N0c, N0d */
               || bidi_it->bracket_enclosed_type == STRONG_R)
        {
-         eassert (bidi_it->prev_for_neutral.type != UNKNOWN_BT);
-         switch (bidi_it->prev_for_neutral.type)
+         bidi_type_t prev_type_for_neutral = bidi_it->prev_for_neutral.type;
+
+         if (prev_type_for_neutral == UNKNOWN_BT)
+           prev_type_for_neutral = embedding_type;
+         switch (prev_type_for_neutral)
            {
            case STRONG_R:
            case WEAK_EN: