Merge pull request #1883 from khaledhosny/script-reset

[feaLib] Ignore superfluous script statements

Lib/fontTools/feaLib/builder.py

@@ -706,6 +706,10 @@ class Builder(object):
             raise FeatureLibError(
                 "Language statements are not allowed "
                 "within \"feature %s\"" % self.cur_feature_name_, location)
+        if self.cur_feature_name_ is None:
+            raise FeatureLibError(
+                "Language statements are not allowed "
+                "within standalone lookup blocks", location)
         self.cur_lookup_ = None
 
         key = (self.script_, language, self.cur_feature_name_)
@@ -772,6 +776,13 @@ class Builder(object):
             raise FeatureLibError(
                 "Script statements are not allowed "
                 "within \"feature %s\"" % self.cur_feature_name_, location)
+        if self.cur_feature_name_ is None:
+            raise FeatureLibError(
+                "Script statements are not allowed "
+                "within standalone lookup blocks", location)
+        if self.language_systems == {(script, 'dflt')}:
+            # Nothing to do.
+            return
         self.cur_lookup_ = None
         self.script_ = script
         self.lookupflag_ = 0

Tests/feaLib/builder_test.py

@@ -337,6 +337,12 @@ class BuilderTest(unittest.TestCase):
             "Script statements are not allowed within \"feature size\"",
             self.build, "feature size { script latn; } size;")
 
+    def test_script_in_standalone_lookup(self):
+        self.assertRaisesRegex(
+            FeatureLibError,
+            "Script statements are not allowed within standalone lookup blocks",
+            self.build, "lookup test { script latn; } test;")
+
     def test_language(self):
         builder = Builder(makeTTFont(), (None, None))
         builder.add_language_system(None, 'latn', 'FRA ')
@@ -364,6 +370,12 @@ class BuilderTest(unittest.TestCase):
             "Language statements are not allowed within \"feature size\"",
             self.build, "feature size { language FRA; } size;")
 
+    def test_language_in_standalone_lookup(self):
+        self.assertRaisesRegex(
+            FeatureLibError,
+            "Language statements are not allowed within standalone lookup blocks",
+            self.build, "lookup test { language FRA; } test;")
+
     def test_language_required_duplicate(self):
         self.assertRaisesRegex(
             FeatureLibError,

Tests/feaLib/data/lookupflag.fea

@@ -134,3 +134,16 @@ feature test {
         pos one 1;
     } V;
 } test;
+
+feature test {
+    lookup W {
+        lookupflag IgnoreMarks;
+        script latn;
+        pos one 1;
+    } W;
+    lookup X {
+        lookupflag IgnoreMarks;
+        script latn;
+        pos two 2;
+    } X;
+} test;

Tests/feaLib/data/lookupflag.ttx

@@ -43,7 +43,7 @@
   <GPOS>
     <Version value="0x00010000"/>
     <ScriptList>
-      <!-- ScriptCount=1 -->
+      <!-- ScriptCount=2 -->
       <ScriptRecord index="0">
         <ScriptTag value="DFLT"/>
         <Script>
@@ -55,9 +55,20 @@
           <!-- LangSysCount=0 -->
         </Script>
       </ScriptRecord>
+      <ScriptRecord index="1">
+        <ScriptTag value="latn"/>
+        <Script>
+          <DefaultLangSys>
+            <ReqFeatureIndex value="65535"/>
+            <!-- FeatureCount=1 -->
+            <FeatureIndex index="0" value="1"/>
+          </DefaultLangSys>
+          <!-- LangSysCount=0 -->
+        </Script>
+      </ScriptRecord>
     </ScriptList>
     <FeatureList>
-      <!-- FeatureCount=1 -->
+      <!-- FeatureCount=2 -->
       <FeatureRecord index="0">
         <FeatureTag value="test"/>
         <Feature>
@@ -86,9 +97,17 @@
           <LookupListIndex index="21" value="21"/>
         </Feature>
       </FeatureRecord>
+      <FeatureRecord index="1">
+        <FeatureTag value="test"/>
+        <Feature>
+          <!-- LookupCount=2 -->
+          <LookupListIndex index="0" value="22"/>
+          <LookupListIndex index="1" value="23"/>
+        </Feature>
+      </FeatureRecord>
     </FeatureList>
     <LookupList>
-      <!-- LookupCount=22 -->
+      <!-- LookupCount=24 -->
       <Lookup index="0">
         <LookupType value="1"/>
         <LookupFlag value="1"/><!-- rightToLeft -->
@@ -357,6 +376,30 @@
           <Value XAdvance="1"/>
         </SinglePos>
       </Lookup>
+      <Lookup index="22">
+        <LookupType value="1"/>
+        <LookupFlag value="0"/>
+        <!-- SubTableCount=1 -->
+        <SinglePos index="0" Format="1">
+          <Coverage>
+            <Glyph value="one"/>
+          </Coverage>
+          <ValueFormat value="4"/>
+          <Value XAdvance="1"/>
+        </SinglePos>
+      </Lookup>
+      <Lookup index="23">
+        <LookupType value="1"/>
+        <LookupFlag value="8"/><!-- ignoreMarks -->
+        <!-- SubTableCount=1 -->
+        <SinglePos index="0" Format="1">
+          <Coverage>
+            <Glyph value="two"/>
+          </Coverage>
+          <ValueFormat value="4"/>
+          <Value XAdvance="2"/>
+        </SinglePos>
+      </Lookup>
     </LookupList>
   </GPOS>