[indic] Recover OT_H undergone ligation and multiplication
Sometimes font designers form half/pref/etc consonant forms
unconditionally and then undo that conditionally. Try to
recover the OT_H classification in those cases.
No test number changes expected.
diff --git a/src/hb-ot-layout-private.hh b/src/hb-ot-layout-private.hh
index 3ded92f..e66e19c 100644
--- a/src/hb-ot-layout-private.hh
+++ b/src/hb-ot-layout-private.hh
@@ -395,6 +395,14 @@
return _hb_glyph_info_ligated (info) && !_hb_glyph_info_multiplied (info);
}
+static inline void
+_hb_glyph_info_clear_ligated_and_multiplied (hb_glyph_info_t *info)
+{
+ info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_LIGATED |
+ HB_OT_LAYOUT_GLYPH_PROPS_MULTIPLIED);
+}
+
+
/* Allocation / deallocation. */
static inline void
diff --git a/src/hb-ot-shape-complex-indic.cc b/src/hb-ot-shape-complex-indic.cc
index 81f4c61..62f1172 100644
--- a/src/hb-ot-shape-complex-indic.cc
+++ b/src/hb-ot-shape-complex-indic.cc
@@ -1336,6 +1336,27 @@
const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data;
hb_glyph_info_t *info = buffer->info;
+
+ /* This function relies heavily on halant glyphs. Lots of ligation
+ * and possibly multiplication substitutions happened prior to this
+ * phase, and that might have messed up our properties. Recover
+ * from a particular case of that where we're fairly sure that a
+ * class of OT_H is desired but has been lost. */
+ if (indic_plan->virama_glyph)
+ {
+ unsigned int virama_glyph = indic_plan->virama_glyph;
+ for (unsigned int i = start; i < end; i++)
+ if (info[i].codepoint == virama_glyph &&
+ _hb_glyph_info_ligated (&info[i]) &&
+ _hb_glyph_info_multiplied (&info[i]))
+ {
+ /* This will make sure that this glyph passes is_halant_or_coeng() test. */
+ info[i].indic_category() = OT_H;
+ _hb_glyph_info_clear_ligated_and_multiplied (&info[i]);
+ }
+ }
+
+
/* 4. Final reordering:
*
* After the localized forms and basic shaping forms GSUB features have been
