Tighten ccc-setting a bit and document it
diff --git a/src/hb-ot-layout-private.hh b/src/hb-ot-layout-private.hh
index e13eaae..80a8854 100644
--- a/src/hb-ot-layout-private.hh
+++ b/src/hb-ot-layout-private.hh
@@ -235,8 +235,18 @@
if (u == 0x200Cu) props |= UPROPS_MASK_ZWNJ;
if (u == 0x200Du) props |= UPROPS_MASK_ZWJ;
}
- else if (unlikely (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (gen_cat)))
+ else if (unlikely (HB_UNICODE_GENERAL_CATEGORY_IS_NON_ENCLOSING_MARK (gen_cat)))
{
+ /* Only Mn and Mc can have non-zero ccc:
+ * http://www.unicode.org/policies/stability_policy.html#Property_Value
+ * """
+ * Canonical_Combining_Class, General_Category
+ * All characters other than those with General_Category property values
+ * Spacing_Mark (Mc) and Nonspacing_Mark (Mn) have the Canonical_Combining_Class
+ * property value 0.
+ * 1.1.5+
+ * """
+ */
props |= unicode->modified_combining_class (info->codepoint)<<8;
}
}
diff --git a/src/hb-unicode-private.hh b/src/hb-unicode-private.hh
index 968bca5..e729826 100644
--- a/src/hb-unicode-private.hh
+++ b/src/hb-unicode-private.hh
@@ -313,5 +313,10 @@
FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) | \
FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)))
+#define HB_UNICODE_GENERAL_CATEGORY_IS_NON_ENCLOSING_MARK(gen_cat) \
+ (FLAG_SAFE (gen_cat) & \
+ (FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK) | \
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)))
+
#endif /* HB_UNICODE_PRIVATE_HH */
