Merge pull request #2684 from fonttools/fix-ps-name-regression

[designspaceLib] Don't make up bad PS names when no STAT data

Lib/fontTools/designspaceLib/statNames.py

@@ -88,21 +88,30 @@ def getStatNames(
         # Then build names for all these languages, but fallback to English
         # whenever a translation is missing.
         labels = _getAxisLabelsForUserLocation(doc.axes, userLocation)
-        languages = set(language for label in labels for language in label.labelNames)
-        languages.add("en")
-        for language in languages:
-            styleName = " ".join(
-                label.labelNames.get(language, label.defaultName)
-                for label in labels
-                if not label.elidable
-            )
-            if not styleName and doc.elidedFallbackName is not None:
-                styleName = doc.elidedFallbackName
-            styleNames[language] = styleName
+        if labels:
+            languages = set(language for label in labels for language in label.labelNames)
+            languages.add("en")
+            for language in languages:
+                styleName = " ".join(
+                    label.labelNames.get(language, label.defaultName)
+                    for label in labels
+                    if not label.elidable
+                )
+                if not styleName and doc.elidedFallbackName is not None:
+                    styleName = doc.elidedFallbackName
+                styleNames[language] = styleName
 
-    postScriptFontName = None
-    if "en" in familyNames and "en" in styleNames:
-        postScriptFontName = f"{familyNames['en']}-{styleNames['en']}".replace(" ", "")
+    if "en" not in familyNames or "en" not in styleNames:
+        # Not enough information to compute PS names of styleMap names
+        return StatNames(
+            familyNames=familyNames,
+            styleNames=styleNames,
+            postScriptFontName=None,
+            styleMapFamilyNames={},
+            styleMapStyleName=None,
+        )
+
+    postScriptFontName = f"{familyNames['en']}-{styleNames['en']}".replace(" ", "")
 
     styleMapStyleName, regularUserLocation = _getRibbiStyle(doc, userLocation)
 

Tests/designspaceLib/data/DS5BreakTest.designspace

@@ -0,0 +1,56 @@
+<designspace format="4.0">
+    <axes>
+        <axis default="400" maximum="800" minimum="200" name="Weight" tag="wght">
+            <map input="200" output="0" />
+            <map input="400" output="250" />
+            <map input="800" output="1000" />
+        </axis>
+    </axes>
+
+    <sources>
+        <source familyname="DS5BreakTest" filename="DS5BreakTest-Extralight.ufo" stylename="ExtraLight Condensed">
+            <location>
+                <dimension name="Weight" xvalue="0" />
+            </location>
+        </source>
+        <source familyname="DS5BreakTest" filename="DS5BreakTest-Regular.ufo" stylename="Regular">
+            <location>
+                <dimension name="Weight" xvalue="250" />
+            </location>
+        </source>
+        <source familyname="DS5BreakTest" filename="DS5BreakTest-Extrabold.ufo" stylename="ExtraBold">
+            <location>
+                <dimension name="Weight" xvalue="1000" />
+            </location>
+        </source>
+    </sources>
+
+    <instances>
+        <instance familyname="DS5BreakTest" stylename="ExtraLight">
+            <location>
+                <dimension name="Weight" xvalue="0" />
+            </location>
+        </instance>
+        <instance familyname="DS5BreakTest" stylename="Regular">
+            <location>
+                <dimension name="Weight" xvalue="250" />
+            </location>
+        </instance>
+        <instance familyname="DS5BreakTest" stylename="Medium">
+            <location>
+                <dimension name="Weight" xvalue="400" />
+            </location>
+        </instance>
+        <instance familyname="DS5BreakTest" stylename="Bold">
+            <location>
+                <dimension name="Weight" xvalue="750" />
+            </location>
+        </instance>
+        <instance familyname="DS5BreakTest" stylename="ExtraBold">
+            <location>
+                <dimension name="Weight" xvalue="1000" />
+            </location>
+        </instance>
+    </instances>
+
+</designspace>

Tests/designspaceLib/statNames_test.py

@@ -59,3 +59,20 @@ def test_detect_ribbi_aktiv(datadir):
         styleMapFamilyNames={"en": "Aktiv Grotesk Cd"},
         styleMapStyleName="bold italic",
     )
+
+
+def test_getStatNames_on_ds4_doesnt_make_up_bad_names(datadir):
+    """See this issue on GitHub: https://github.com/googlefonts/ufo2ft/issues/630
+
+    When as in the example, there's no STAT data present, the getStatName
+    shouldn't try making up a postscript name.
+    """
+    doc = DesignSpaceDocument.fromfile(datadir / "DS5BreakTest.designspace")
+
+    assert getStatNames(doc, {"Weight": 600, "Width": 125, "Italic": 1}) == StatNames(
+        familyNames={"en": "DS5BreakTest"},
+        styleNames={},
+        postScriptFontName=None,
+        styleMapFamilyNames={},
+        styleMapStyleName=None,
+    )