Add legacy emoji font file for compatibility

Bug: 222362958
Test: Manually verified Flutter Gallary shows emoji.
Test: atest CtsTextTestCases CtsGraphicsTestCases
Test: atest FontListParserTest

Change-Id: If5b5ddfb6d0d46cfb8d27cf66843ae95d4b50e03

core/tests/coretests/src/android/graphics/FontListParserTest.java

@@ -355,6 +355,27 @@ public final class FontListParserTest {
         assertThat(config.getAliases()).isEmpty();
     }
 
+    @Test
+    public void ignore() throws Exception {
+        String xml = "<?xml version='1.0' encoding='UTF-8'?>"
+                + "<familyset>"
+                + "  <family name='sans-serif'>"
+                + "    <font>test.ttf</font>"
+                + "  </family>"
+                + "  <family lang='und-Zsye' ignore='true'>"
+                + "    <font>emoji_legacy.ttf</font>"
+                + "  </family>"
+                + "  <family lang='und-Zsye'>"
+                + "    <font>emoji.ttf</font>"
+                + "  </family>"
+                + "</familyset>";
+        FontConfig config = readFamilies(xml, true /* include non-existing font files */);
+        List<FontConfig.FontFamily> families = config.getFontFamilies();
+        assertThat(families.size()).isEqualTo(2);  // legacy one should be ignored.
+        assertThat(families.get(1).getFontList().get(0).getFile().getName())
+                .isEqualTo("emoji.ttf");
+    }
+
     private FontConfig readFamilies(String xml, boolean allowNonExisting)
             throws IOException, XmlPullParserException {
         ByteArrayInputStream buffer = new ByteArrayInputStream(

data/fonts/fonts.xml

@@ -1328,6 +1328,9 @@
               postScriptName="NotoSerifCJKjp-Regular">NotoSerifCJK-Regular.ttc
         </font>
     </family>
+    <family lang="und-Zsye" ignore="true">
+        <font weight="400" style="normal">NotoColorEmojiLegacy.ttf</font>
+    </family>
     <family lang="und-Zsye">
         <font weight="400" style="normal">NotoColorEmoji.ttf</font>
     </family>

graphics/java/android/graphics/FontListParser.java

@@ -218,6 +218,7 @@ public class FontListParser {
         final String name = parser.getAttributeValue(null, "name");
         final String lang = parser.getAttributeValue("", "lang");
         final String variant = parser.getAttributeValue(null, "variant");
+        final String ignore = parser.getAttributeValue(null, "ignore");
         final List<FontConfig.Font> fonts = new ArrayList<>();
         while (keepReading(parser)) {
             if (parser.getEventType() != XmlPullParser.START_TAG) continue;
@@ -240,7 +241,9 @@ public class FontListParser {
                 intVariant = FontConfig.FontFamily.VARIANT_ELEGANT;
             }
         }
-        if (fonts.isEmpty()) {
+
+        boolean skip = (ignore != null && (ignore.equals("true") || ignore.equals("1")));
+        if (skip || fonts.isEmpty()) {
             return null;
         }
         return new FontConfig.FontFamily(fonts, name, LocaleList.forLanguageTags(lang), intVariant);

tools/fonts/fontchain_linter.py

@@ -243,6 +243,8 @@ def parse_fonts_xml(fonts_xml_path):
         name = family.get('name')
         variant = family.get('variant')
         langs = family.get('lang')
+        ignoreAttr = family.get('ignore')
+
         if name:
             assert variant is None, (
                 'No variant expected for LGC font %s.' % name)
@@ -259,6 +261,11 @@ def parse_fonts_xml(fonts_xml_path):
         name = family.get('name')
         variant = family.get('variant')
         langs = family.get('lang')
+        ignoreAttr = family.get('ignore')
+        ignore = ignoreAttr == 'true' or ignoreAttr == '1'
+
+        if ignore:
+            continue
 
         if langs:
             langs = langs.split()