From 83dbae1da5164bcb2a410cb22a34f67d1de69403 Mon Sep 17 00:00:00 2001
From: Sascha Brawer <sascha@brawer.ch>
Date: Mon, 7 Dec 2015 11:47:55 +0100
Subject: [PATCH] [feaLib] Do not emit any Value if ValueFormat is 0

---
 Lib/fontTools/feaLib/builder.py          |  6 +++++-
 Lib/fontTools/feaLib/testdata/GPOS_1.fea |  2 ++
 Lib/fontTools/feaLib/testdata/GPOS_1.ttx | 14 ++++++++++----
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/Lib/fontTools/feaLib/builder.py b/Lib/fontTools/feaLib/builder.py
index 47342a6d3..d887f9594 100644
--- a/Lib/fontTools/feaLib/builder.py
+++ b/Lib/fontTools/feaLib/builder.py
@@ -364,7 +364,11 @@ def makeOpenTypeValueRecord(v):
     for mask, name, _, _ in otBase.valueRecordFormat:
         if getattr(vr, name, 0) != 0:
             vrMask |= mask
-    return vr, vrMask
+
+    if vrMask == 0:
+        return None, 0
+    else:
+        return vr, vrMask
 
 
 class LookupBuilder(object):
diff --git a/Lib/fontTools/feaLib/testdata/GPOS_1.fea b/Lib/fontTools/feaLib/testdata/GPOS_1.fea
index 9f836ce0d..e0bc992ff 100644
--- a/Lib/fontTools/feaLib/testdata/GPOS_1.fea
+++ b/Lib/fontTools/feaLib/testdata/GPOS_1.fea
@@ -3,6 +3,8 @@ languagesystem DFLT dflt;
 @sevenEightNine = [seven eight nine];
 
 feature kern {
+    position zero 0;
+
     position [one two three] <-80 0 -160 0>;
     position A <
         1 2 3 4
diff --git a/Lib/fontTools/feaLib/testdata/GPOS_1.ttx b/Lib/fontTools/feaLib/testdata/GPOS_1.ttx
index d8bbca652..10c5890d9 100644
--- a/Lib/fontTools/feaLib/testdata/GPOS_1.ttx
+++ b/Lib/fontTools/feaLib/testdata/GPOS_1.ttx
@@ -53,7 +53,7 @@
       <Lookup index="0">
         <!-- LookupType=1 -->
         <LookupFlag value="0"/>
-        <!-- SubTableCount=7 -->
+        <!-- SubTableCount=8 -->
         <SinglePos index="0" Format="2">
           <Coverage>
             <Glyph value="four"/>
@@ -91,6 +91,12 @@
           <Value index="2" XPlacement="1" YPlacement="1" XAdvance="805"/>
         </SinglePos>
         <SinglePos index="3" Format="1">
+          <Coverage>
+            <Glyph value="zero"/>
+          </Coverage>
+          <ValueFormat value="0"/>
+        </SinglePos>
+        <SinglePos index="4" Format="1">
           <Coverage>
             <Glyph value="one"/>
             <Glyph value="two"/>
@@ -100,7 +106,7 @@
           <ValueFormat value="5"/>
           <Value XPlacement="-80" XAdvance="-160"/>
         </SinglePos>
-        <SinglePos index="4" Format="1">
+        <SinglePos index="5" Format="1">
           <Coverage>
             <Glyph value="seven"/>
             <Glyph value="eight"/>
@@ -109,7 +115,7 @@
           <ValueFormat value="4"/>
           <Value XAdvance="-100"/>
         </SinglePos>
-        <SinglePos index="5" Format="1">
+        <SinglePos index="6" Format="1">
           <Coverage>
             <Glyph value="A"/>
             <Glyph value="B"/>
@@ -136,7 +142,7 @@
             </XAdvDevice>
           </Value>
         </SinglePos>
-        <SinglePos index="6" Format="1">
+        <SinglePos index="7" Format="1">
           <Coverage>
             <Glyph value="C"/>
           </Coverage>