Pass through unknown ISO 639-3 language tags to OpenType engine
In hb_ot_tag_from_language(), if first component of an unknown
language is three letters long, use it directly as OpenType language
tag (after case conversion and padding).
diff --git a/src/hb-ot-tag.cc b/src/hb-ot-tag.cc
index dcae8f1..ac60e96 100644
--- a/src/hb-ot-tag.cc
+++ b/src/hb-ot-tag.cc
@@ -651,6 +651,14 @@
return HB_TAG('Z','H','S',' ');
}
+ s = strchr (lang_str, '-');
+ if (!s)
+ s = lang_str + strlen (lang_str);
+ if (s - lang_str == 3) {
+ /* Assume it's ISO-639-3 and upper-case and use it. */
+ return hb_tag_from_string (lang_str, s - lang_str) & ~0x20202000;
+ }
+
return HB_OT_TAG_DEFAULT_LANGUAGE;
}
diff --git a/test/test-ot-tag.c b/test/test-ot-tag.c
index a00799d..81b6678 100644
--- a/test/test-ot-tag.c
+++ b/test/test-ot-tag.c
@@ -213,12 +213,17 @@
test_tag_from_language ("dflt", "asdf-asdf-wer-x-hbot-zxc");
+ test_tag_from_language ("dflt", "xy");
+ test_tag_from_language ("XYZ", "xyz"); /* Unknown ISO 639-3 */
+ test_tag_from_language ("XYZ", "xyz-qw"); /* Unknown ISO 639-3 */
+
/* Test that x-hbot overrides the base language */
test_tag_from_language ("ABC", "fa-x-hbotabc-zxc");
test_tag_from_language ("ABC", "fa-ir-x-hbotabc-zxc");
test_tag_from_language ("ABC", "zh-x-hbotabc-zxc");
test_tag_from_language ("ABC", "zh-cn-x-hbotabc-zxc");
test_tag_from_language ("ABC", "zh-xy-x-hbotabc-zxc");
+ test_tag_from_language ("ABC", "xyz-xy-x-hbotabc-zxc");
}
int
