From 7ed4c43395ffb2fb34a283f05309e4cf72b99a43 Mon Sep 17 00:00:00 2001
From: Rob McKaughan <robmck@microsoft.com>
Date: Tue, 20 Jun 2017 15:01:23 -0700
Subject: [PATCH] Do not emit MVAR if there are no entries in the variation
 store

---
 Lib/fontTools/varLib/__init__.py | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/Lib/fontTools/varLib/__init__.py b/Lib/fontTools/varLib/__init__.py
index 259074c09..1c3f9e08e 100644
--- a/Lib/fontTools/varLib/__init__.py
+++ b/Lib/fontTools/varLib/__init__.py
@@ -414,13 +414,14 @@ def _add_MVAR(font, model, master_ttfs, axisTags):
 		rec.VarIdx = varIdx
 		records.append(rec)
 
-	assert "MVAR" not in font
-	MVAR = font["MVAR"] = newTable('MVAR')
-	mvar = MVAR.table = ot.MVAR()
-	mvar.Version = 0x00010000
-	mvar.Reserved = 0
-	mvar.VarStore = store_builder.finish()
-	mvar.ValueRecord = sorted(records, key=lambda r: r.ValueTag)
+	if len(records) > 0 :
+		assert "MVAR" not in font
+		MVAR = font["MVAR"] = newTable('MVAR')
+		mvar = MVAR.table = ot.MVAR()
+		mvar.Version = 0x00010000
+		mvar.Reserved = 0
+		mvar.VarStore = store_builder.finish()
+		mvar.ValueRecord = sorted(records, key=lambda r: r.ValueTag)
 
 
 def _merge_OTL(font, model, master_fonts, axisTags):