[ttLib/glyf] raise TTLibError with the offending glyph name in the error message when a component (indirectly) references itself

Lib/fontTools/ttLib/tables/_g_l_y_f.py

@@ -841,7 +841,10 @@ class Glyph(object):
 			allEndPts = []
 			for compo in self.components:
 				g = glyfTable[compo.glyphName]
-				coordinates, endPts, flags = g.getCoordinates(glyfTable)
+				try:
+					coordinates, endPts, flags = g.getCoordinates(glyfTable)
+				except RuntimeError:
+					raise ttLib.TTLibError("glyph '%s' contains recursive component reference" % compo.glyphName)
 				if hasattr(compo, "firstPt"):
 					# move according to two reference points
 					x1,y1 = allCoords[compo.firstPt]

Tests/ttLib/tables/_g_l_y_f_test.py

@@ -1,7 +1,8 @@
 from __future__ import print_function, division, absolute_import
 from fontTools.misc.py23 import *
 from fontTools.misc.fixedTools import otRound
-from fontTools.ttLib import TTFont, newTable
+from fontTools.pens.ttGlyphPen import TTGlyphPen
+from fontTools.ttLib import TTFont, newTable, TTLibError
 from fontTools.ttLib.tables._g_l_y_f import GlyphCoordinates
 import sys
 import array
@@ -180,6 +181,13 @@ def strip_ttLibVersion(string):
 
 class glyfTableTest(unittest.TestCase):
 
+    def __init__(self, methodName):
+        unittest.TestCase.__init__(self, methodName)
+        # Python 3 renamed assertRaisesRegexp to assertRaisesRegex,
+        # and fires deprecation warnings if a program uses the old name.
+        if not hasattr(self, "assertRaisesRegex"):
+            self.assertRaisesRegex = self.assertRaisesRegexp
+
     @classmethod
     def setUpClass(cls):
         with open(GLYF_BIN, 'rb') as f:
@@ -215,6 +223,23 @@ class glyfTableTest(unittest.TestCase):
         glyfData = glyfTable.compile(font)
         self.assertEqual(glyfData, self.glyfData)
 
+    def test_recursiveComponent(self):
+        glyphSet = {}
+        pen_dummy = TTGlyphPen(glyphSet)
+        glyph_dummy = pen_dummy.glyph()
+        glyphSet["A"] = glyph_dummy
+        glyphSet["B"] = glyph_dummy
+        pen_A = TTGlyphPen(glyphSet)
+        pen_A.addComponent("B", (1, 0, 0, 1, 0, 0))
+        pen_B = TTGlyphPen(glyphSet)
+        pen_B.addComponent("A", (1, 0, 0, 1, 0, 0))
+        glyph_A = pen_A.glyph()
+        glyph_B = pen_B.glyph()
+        glyphSet["A"] = glyph_A
+        glyphSet["B"] = glyph_B
+        with self.assertRaisesRegex(TTLibError, "glyph '.' contains recursive component reference"):
+            glyph_A.getCoordinates(glyphSet)
+
 
 if __name__ == "__main__":
     import sys