1 files changed, 42 insertions, 2 deletions
diff --git a/Lib/fontTools/designspaceLib/split.py b/Lib/fontTools/designspaceLib/split.py
index 408de70a..0b7cdf4b 100644
--- a/Lib/fontTools/designspaceLib/split.py
+++ b/Lib/fontTools/designspaceLib/split.py
@@ -11,6 +11,7 @@ from typing import Any, Callable, Dict, Iterator, List, Tuple, cast
 
 from fontTools.designspaceLib import (
     AxisDescriptor,
+    AxisMappingDescriptor,
     DesignSpaceDocument,
     DiscreteAxisDescriptor,
     InstanceDescriptor,
@@ -225,6 +226,44 @@ def _extractSubSpace(
                 )
             )
 
+    subDoc.axisMappings = mappings = []
+    subDocAxes = {axis.name for axis in subDoc.axes}
+    for mapping in doc.axisMappings:
+        if not all(axis in subDocAxes for axis in mapping.inputLocation.keys()):
+            continue
+        if not all(axis in subDocAxes for axis in mapping.outputLocation.keys()):
+            LOGGER.error(
+                "In axis mapping from input %s, some output axes are not in the variable-font: %s",
+                mapping.inputLocation,
+                mapping.outputLocation,
+            )
+            continue
+
+        mappingAxes = set()
+        mappingAxes.update(mapping.inputLocation.keys())
+        mappingAxes.update(mapping.outputLocation.keys())
+        for axis in doc.axes:
+            if axis.name not in mappingAxes:
+                continue
+            range = userRegion[axis.name]
+            if (
+                range.minimum != axis.minimum
+                or (range.default is not None and range.default != axis.default)
+                or range.maximum != axis.maximum
+            ):
+                LOGGER.error(
+                    "Limiting axis ranges used in <mapping> elements not supported: %s",
+                    axis.name,
+                )
+                continue
+
+        mappings.append(
+            AxisMappingDescriptor(
+                inputLocation=mapping.inputLocation,
+                outputLocation=mapping.outputLocation,
+            )
+        )
+
     # Don't include STAT info
     # subDoc.locationLabels = doc.locationLabels
 
@@ -352,9 +391,10 @@ def _extractSubSpace(
 def _conditionSetFrom(conditionSet: List[Dict[str, Any]]) -> ConditionSet:
     c: Dict[str, Range] = {}
     for condition in conditionSet:
+        minimum, maximum = condition.get("minimum"), condition.get("maximum")
         c[condition["name"]] = Range(
-            condition.get("minimum", -math.inf),
-            condition.get("maximum", math.inf),
+            minimum if minimum is not None else -math.inf,
+            maximum if maximum is not None else math.inf,
         )
     return c