From f6e2e5f78606741b7ab824e9161fa96f2ab93f94 Mon Sep 17 00:00:00 2001
From: Just van Rossum <justvanrossum@gmail.com>
Date: Sat, 16 Dec 2023 10:36:00 +0100
Subject: [PATCH 1/2] add more test cases for invalid input; add some type
 annotations

---
 test-py/test_clipboard.py | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/test-py/test_clipboard.py b/test-py/test_clipboard.py
index 5fc45720e..64affd024 100644
--- a/test-py/test_clipboard.py
+++ b/test-py/test_clipboard.py
@@ -9,6 +9,8 @@
     "inputData, expectedResult",
     [
         ("dasasdad", None),  # unparsable
+        ("<svg xxxx", None),  # unparsable
+        ("<?xml xxxx <glyph ", None),  # unparsable
         (
             '<svg xmlns="http://www.w3.org/2000/svg" width="50" '
             'height="120" viewBox="60 0 50 120">'
@@ -68,10 +70,8 @@
         ),
     ],
 )
-def test_parseClipboard(inputData, expectedResult):
-    result = parseClipboard(inputData)
-    if result is not None:
-        result = result
+def test_parseClipboard(inputData: str, expectedResult: StaticGlyph):
+    result: StaticGlyph | None = parseClipboard(inputData)
     assert expectedResult == result
 
 
@@ -113,8 +113,8 @@ def test_parseClipboard(inputData, expectedResult):
         ),
     ],
 )
-def test_serializeStaticGlyphAsGLIF(glyphName, glyph, unicodes, expectedResult):
-    result = serializeStaticGlyphAsGLIF(glyphName, glyph, unicodes)
-    if result is not None:
-        result = result
+def test_serializeStaticGlyphAsGLIF(
+    glyphName: str, glyph: StaticGlyph, unicodes: list[int], expectedResult: str
+):
+    result: str = serializeStaticGlyphAsGLIF(glyphName, glyph, unicodes)
     assert expectedResult == result

From e5766b91530bb165d406965e049aef58da5f54bb Mon Sep 17 00:00:00 2001
From: Just van Rossum <justvanrossum@gmail.com>
Date: Sat, 16 Dec 2023 10:37:26 +0100
Subject: [PATCH 2/2] Add type annotations, and handle invalid input better

---
 src/fontra/core/clipboard.py | 34 +++++++++++++++++++++++-----------
 1 file changed, 23 insertions(+), 11 deletions(-)

diff --git a/src/fontra/core/clipboard.py b/src/fontra/core/clipboard.py
index 51a1e0c3b..44e6c2cc4 100644
--- a/src/fontra/core/clipboard.py
+++ b/src/fontra/core/clipboard.py
@@ -1,8 +1,11 @@
+from xml.etree.ElementTree import ParseError
+
 from fontTools.pens.boundsPen import ControlBoundsPen
 from fontTools.pens.pointPen import GuessSmoothPointPen, SegmentToPointPen
 from fontTools.pens.recordingPen import RecordingPen
 from fontTools.pens.transformPen import TransformPointPen
 from fontTools.svgLib import SVGPath
+from fontTools.ufoLib.errors import GlifLibError
 from fontTools.ufoLib.glifLib import readGlyphFromString, writeGlyphToString
 
 from ..backends.designspace import UFOGlyph, populateUFOLayerGlyph, readGlyphOrCreate
@@ -10,7 +13,7 @@
 from .path import PackedPathPointPen
 
 
-def parseClipboard(data):
+def parseClipboard(data: str) -> StaticGlyph | None:
     if "<svg" in data:
         return parseSVG(data)
     if "<?xml" in data and "<glyph " in data:
@@ -18,9 +21,13 @@ def parseClipboard(data):
     return None
 
 
-def parseSVG(data):
-    data = data.encode("utf-8")
-    svgPath = SVGPath.fromstring(data, transform=(1, 0, 0, -1, 0, 0))
+def parseSVG(data: str) -> StaticGlyph | None:
+    try:
+        svgPath = SVGPath.fromstring(
+            data.encode("utf-8"), transform=(1, 0, 0, -1, 0, 0)
+        )
+    except ParseError:
+        return None
     recPen = RecordingPen()
     svgPath.draw(recPen)
     boundsPen = ControlBoundsPen(None)
@@ -36,20 +43,25 @@ def parseSVG(data):
     return StaticGlyph(path=pen.getPath(), xAdvance=xMax)
 
 
-def parseGLIF(data):
+def parseGLIF(data: str) -> StaticGlyph | None:
     pen = PackedPathPointPen()
     ufoGlyph = UFOGlyph()
-    readGlyphFromString(
-        data,
-        glyphObject=ufoGlyph,
-        pointPen=pen,
-    )
+    try:
+        readGlyphFromString(
+            data,
+            glyphObject=ufoGlyph,
+            pointPen=pen,
+        )
+    except GlifLibError:
+        return None
     return StaticGlyph(
         path=pen.getPath(), components=pen.components, xAdvance=ufoGlyph.width
     )
 
 
-def serializeStaticGlyphAsGLIF(glyphName, staticGlyph, unicodes):
+def serializeStaticGlyphAsGLIF(
+    glyphName: str, staticGlyph: StaticGlyph, unicodes: list[int]
+) -> str:
     layerGlyph = readGlyphOrCreate({}, glyphName, unicodes)
     drawPointsFunc = populateUFOLayerGlyph(layerGlyph, staticGlyph)
     return writeGlyphToString(glyphName, layerGlyph, drawPointsFunc, validate=False)