[Indic] Break syllables at Halant,ZWNJ

That's really what Uniscribe does, and explains a lot of pecularities of
Halant,ZWNJ before the base.

Sent Telugu from 1% failures to 0.03%.  Improved Kannada and Malayalam
slightly.  Fixed half of Bengali, and did NOT break anything!

diff --git a/src/hb-ot-shape-complex-indic-machine.rl b/src/hb-ot-shape-complex-indic-machine.rl
index 4501773..4be7698 100644 (file)
--- a/src/hb-ot-shape-complex-indic-machine.rl
+++ b/src/hb-ot-shape-complex-indic-machine.rl
@@ -67,8 +67,9 @@ forced_rakar = ZWJ H ZWJ Ra;
 matra_group = z*.M.N?.(H | forced_rakar)?;
 syllable_tail = SM? (Coeng (cn|V))? (VD VD?)?;
 place_holder = NBSP | DOTTEDCIRCLE;
-halant_group = (z?.h.z?);
-halant_or_matra_group = (halant_group | matra_group*);
+halant_group = (z?.h.ZWJ?);
+final_halant_group = halant_group | h.ZWNJ;
+halant_or_matra_group = (final_halant_group | matra_group*);
 
 
 consonant_syllable =   Repha? (cn.halant_group)* cn A? halant_or_matra_group? syllable_tail;

diff --git a/src/hb-ot-shape-complex-indic.cc b/src/hb-ot-shape-complex-indic.cc
index 42a7e8d..e771e57 100644 (file)
--- a/src/hb-ot-shape-complex-indic.cc
+++ b/src/hb-ot-shape-complex-indic.cc
@@ -531,9 +531,8 @@ initial_reordering_consonant_syllable (const hb_ot_map_t *map, hb_buffer_t *buff
        }
        else
        {
-         /* A ZWJ at the end of syllable, or any ZWJ/ZWNJ in other places, stop the base
-          * search (to request explicit half or halant forms. */
-         if (is_joiner (info[i]) && (i + 1 < end || info[i].indic_category() == OT_ZWJ))
+         /* A ZWJ stops the base search, and requests an explicit half form. */
+         if (info[i].indic_category() == OT_ZWJ)
            break;
        }
       } while (i > limit);