[buildcff2vf] fix bug 817: unintentional subsetting of features

A side effect of of using the fontTools subsetter module to implement glyph subsetting with the -i option is that features are removed if they are not in the subsetter default features set . Since buildcff2vf  is not intended to filter out features, I fixed this by setting the subsetter module's layout_features option field to '*', which causes it to pass through all features.

python/afdko/buildcff2vf.py

@@ -77,7 +77,7 @@ def getSubset(subset_Path):
 
 def subset_masters(designspace, subsetDict):
     from fontTools import subset
-    subset_options = subset.Options(notdef_outline=True)
+    subset_options = subset.Options(notdef_outline=True, layout_features='*')
     for ds_source in designspace.sources:
         key = tuple(ds_source.location.items())
         included = set(subsetDict[key])

tests/buildcff2vf_data/expected_output/bug817.ttx

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ttFont sfntVersion="OTTO" ttLibVersion="3.43">
+
+  <GSUB>
+    <Version value="0x00010000"/>
+    <ScriptList>
+      <!-- ScriptCount=1 -->
+      <ScriptRecord index="0">
+        <ScriptTag value="DFLT"/>
+        <Script>
+          <DefaultLangSys>
+            <ReqFeatureIndex value="65535"/>
+            <!-- FeatureCount=1 -->
+            <FeatureIndex index="0" value="0"/>
+          </DefaultLangSys>
+          <!-- LangSysCount=0 -->
+        </Script>
+      </ScriptRecord>
+    </ScriptList>
+    <FeatureList>
+      <!-- FeatureCount=1 -->
+      <FeatureRecord index="0">
+        <FeatureTag value="test"/>
+        <Feature>
+          <!-- LookupCount=1 -->
+          <LookupListIndex index="0" value="0"/>
+        </Feature>
+      </FeatureRecord>
+    </FeatureList>
+    <LookupList>
+      <!-- LookupCount=1 -->
+      <Lookup index="0">
+        <LookupType value="1"/>
+        <LookupFlag value="0"/>
+        <!-- SubTableCount=1 -->
+        <SingleSubst index="0" Format="1">
+          <Substitution in="A" out="A"/>
+        </SingleSubst>
+      </Lookup>
+    </LookupList>
+  </GSUB>
+
+</ttFont>

tests/buildcff2vf_data/input/bug817/bug817.designspace

@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="utf-8"?>
+<designspace format="3">
+    <axes>
+        <axis default="368" maximum="1000.0" minimum="0.0" name="weight" tag="wght">
+        </axis>
+    </axes>
+    <sources>
+        <source filename="source_fonts/SourceCode_ExtraLight.ufo" name="master_0">
+            <location>
+                <dimension name="weight" xvalue="0" />
+            </location>
+        </source>
+        <source filename="source_fonts/SourceCode_Regular.ufo" name="master_1">
+            <location>
+                <dimension name="weight" xvalue="368" />
+            </location>
+        </source>
+        <source filename="source_fonts/SourceCode_Black.ufo" name="master_2">
+            <location>
+                <dimension name="weight" xvalue="1000" />
+            </location>
+        </source>
+    </sources>
+    <instances>
+        <instance familyname="Bug 816 TestVF" postscriptfontname="SourceCodeRoman-ExtraLight" stylename="ExtraLight">
+            <location>
+                <dimension name="weight" xvalue="0" />
+            </location>
+        </instance>
+        <instance familyname="Bug 816 TestVF" postscriptfontname="SourceCodeRoman-Regular" stylename="Regular">
+            <location>
+                <dimension name="weight" xvalue="368" />
+            </location>
+        </instance>
+        <instance familyname="Bug 816 TestVF" postscriptfontname="SourceCodeRoman-Black" stylename="Black">
+            <location>
+                <dimension name="weight" xvalue="1000" />
+            </location>
+        </instance>
+    </instances>
+</designspace>

tests/buildcff2vf_data/input/bug817/bug817.subset

@@ -0,0 +1,7 @@
+((('weight',0.0),), (('weight', 368.0),),)
+.notdef
+A
+T
+((('weight',1000.0),),)
+.notdef
+A

tests/buildcff2vf_test.py

@@ -71,3 +71,18 @@ def test_compatibility_vf():
                                    ['CFF2', ])
     expected_ttx = get_expected_path('bug816.ttx')
     assert differ([expected_ttx, actual_ttx, '-s', '<ttFont sfntVersion'])
+
+
+def test_subset_vf():
+    input_dir = get_input_path('bug817')
+    temp_dir = os.path.join(tempfile.mkdtemp(), 'bug817var')
+    copytree(input_dir, temp_dir)
+    ds_path = os.path.join(temp_dir, 'bug817.designspace')
+    subset_path = os.path.join(temp_dir, 'bug817.subset')
+    runner(CMD + ['-o', 'd', '_{}'.format(
+        ds_path), 'i', '_{}'.format(subset_path)])
+    actual_path = os.path.join(temp_dir, 'bug817.otf')
+    actual_ttx = generate_ttx_dump(actual_path,
+                                   ['GSUB', ])
+    expected_ttx = get_expected_path('bug817.ttx')
+    assert differ([expected_ttx, actual_ttx, '-s', '<ttFont sfntVersion'])