From f48051af2391705e13e316437f7b05c2c34b583a Mon Sep 17 00:00:00 2001
From: Nikolaus Waxweiler <nikolaus.waxweiler@daltonmaag.com>
Date: Wed, 12 Jun 2019 14:00:54 +0100
Subject: [PATCH] Fix corrupt class-based pair kerning table merging

---
 Lib/fontTools/varLib/merger.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Lib/fontTools/varLib/merger.py b/Lib/fontTools/varLib/merger.py
index b4b170594..d92eb7fa3 100644
--- a/Lib/fontTools/varLib/merger.py
+++ b/Lib/fontTools/varLib/merger.py
@@ -2,6 +2,7 @@
 Merge OpenType Layout tables (GDEF / GPOS / GSUB).
 """
 from __future__ import print_function, division, absolute_import
+import copy
 from fontTools.misc.py23 import *
 from fontTools.misc.fixedTools import otRound
 from fontTools.misc import classifyTools
@@ -455,7 +456,7 @@ def _PairPosFormat2_align_matrices(self, lst, font, transparent=False):
 					exemplarGlyph = next(iter(classSet))
 					klass = classDef2.get(exemplarGlyph, 0)
 					rec2 = oldClass2Records[klass]
-				class2Records.append(rec2)
+				class2Records.append(copy.deepcopy(rec2))
 			class1Records.append(rec1new)
 		new_matrices.append(class1Records)
 	matrices = new_matrices