Compute the correct source location when a local axis exists with the…

… same name as a global axis

src/fontra/backends/designspace.py

@@ -5,7 +5,7 @@
 import os
 import pathlib
 from collections import defaultdict
-from copy import copy, deepcopy
+from copy import deepcopy
 from dataclasses import asdict, dataclass
 from datetime import datetime
 from functools import cache, cached_property
@@ -205,16 +205,11 @@ async def getGlyph(self, glyphName):
 
         axes = []
         sources = []
+        localSources = []
         layers = {}
         sourceNameMapping = {}
         layerNameMapping = {}
 
-        for dsSource in self.dsSources:
-            glyphSet = dsSource.layer.glyphSet
-            if glyphName not in glyphSet:
-                continue
-            sources.append(dsSource.newFontraSource())
-
         for ufoLayer in self.ufoLayers:
             if glyphName not in ufoLayer.glyphSet:
                 continue
@@ -226,11 +221,24 @@ async def getGlyph(self, glyphName):
                     axes, localSources = self._unpackLocalDesignSpace(
                         localDS, ufoLayer.name
                     )
-                    sources.extend(localSources)
                 sourceNameMapping = ufoGlyph.lib.get(SOURCE_NAME_MAPPING_LIB_KEY, {})
                 layerNameMapping = ufoGlyph.lib.get(LAYER_NAME_MAPPING_LIB_KEY, {})
             layers[ufoLayer.fontraLayerName] = Layer(staticGlyph)
 
+        localDefaultOverride = {
+            axis.name: axis.defaultValue
+            for axis in axes
+            if axis.name in self.defaultLocation
+        }
+
+        for dsSource in self.dsSources:
+            glyphSet = dsSource.layer.glyphSet
+            if glyphName not in glyphSet:
+                continue
+            sources.append(dsSource.newFontraSource(localDefaultOverride))
+
+        sources.extend(localSources)
+
         if layerNameMapping:
             for source in sources:
                 source.layerName = layerNameMapping.get(
@@ -301,15 +309,15 @@ async def putGlyph(self, glyphName, glyph, unicodes):
         )
 
         localAxes = packLocalAxes(glyph.axes)
-        localAxisNames = {axis.name for axis in glyph.axes}
+        localDefaultLocation = {axis.name: axis.defaultValue for axis in glyph.axes}
 
         # Prepare UFO source layers and local sources
         sourceNameMapping = {}
         layerNameMapping = {}
         localSources = []
         for source in glyph.sources:
             sourceInfo = self._prepareUFOSourceLayer(
-                source, localAxisNames, revLayerNameMapping
+                source, localDefaultLocation, revLayerNameMapping
             )
             if sourceInfo.sourceName != source.name:
                 sourceNameMapping[sourceInfo.sourceName] = source.name
@@ -385,10 +393,15 @@ async def putGlyph(self, glyphName, glyph, unicodes):
 
         self.savedGlyphModificationTimes[glyphName] = modTimes
 
-    def _prepareUFOSourceLayer(self, source, localAxisNames, revLayerNameMapping):
+    def _prepareUFOSourceLayer(self, source, localDefaultLocation, revLayerNameMapping):
+        sparseLocalLocation = {
+            name: source.location[name]
+            for name, value in localDefaultLocation.items()
+            if source.location.get(name, value) != value
+        }
         sourceLocation = {**self.defaultLocation, **source.location}
         globalLocation = self._getGlobalPortionOfLocation(
-            sourceLocation, localAxisNames
+            sourceLocation, localDefaultLocation
         )
 
         dsSource = self.dsSources.findItem(
@@ -397,7 +410,7 @@ def _prepareUFOSourceLayer(self, source, localAxisNames, revLayerNameMapping):
         if dsSource is None:
             dsSource = self._createDSSource(source, globalLocation)
 
-        if sourceLocation != globalLocation:
+        if sparseLocalLocation:
             ufoLayer = self.ufoLayers.findItem(
                 fontraLayerName=revLayerNameMapping.get(
                     source.layerName, source.layerName
@@ -717,10 +730,12 @@ class DSSource:
     def locationTuple(self):
         return tuplifyLocation(self.location)
 
-    def newFontraSource(self):
+    def newFontraSource(self, localDefaultOverride=None):
+        if localDefaultOverride is None:
+            localDefaultOverride = {}
         return Source(
             name=self.name,
-            location=copy(self.location),
+            location={**self.location, **localDefaultOverride},
             layerName=self.layer.fontraLayerName,
         )