diff --git a/src/class.js b/src/class.js
index 1919519aa..0d8803d4c 100644
--- a/src/class.js
+++ b/src/class.js
@@ -84,10 +84,8 @@ Class.generate = function generate(type) { // eslint-disable-line no-unused-vars
         else if (field.repeated) gen
             ("this%s=[]", util.safeProp(field.name));
     return gen
-    ("if(p){")
-        ("for(var ks=Object.keys(p),i=0;i<ks.length;++i)")
-            ("this[ks[i]]=p[ks[i]];")
-    ("}");
+    ("if(p)for(var ks=Object.keys(p),i=0;i<ks.length;++i)if(p[ks[i]]!=null)") // omit undefined or null
+        ("this[ks[i]]=p[ks[i]]");
     /* eslint-enable no-unexpected-multiline */
 };
 
diff --git a/tests/data/comments.js b/tests/data/comments.js
index bd1efdb99..6a1ab56f1 100644
--- a/tests/data/comments.js
+++ b/tests/data/comments.js
@@ -33,7 +33,8 @@ $root.Test1 = (function() {
     function Test1(properties) {
         if (properties)
             for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                this[keys[i]] = properties[keys[i]];
+                if (properties[keys[i]] != null)
+                    this[keys[i]] = properties[keys[i]];
     }
 
     /**
@@ -244,7 +245,8 @@ $root.Test2 = (function() {
     function Test2(properties) {
         if (properties)
             for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                this[keys[i]] = properties[keys[i]];
+                if (properties[keys[i]] != null)
+                    this[keys[i]] = properties[keys[i]];
     }
 
     /**
diff --git a/tests/data/convert.js b/tests/data/convert.js
index a42725c8d..d5202d35e 100644
--- a/tests/data/convert.js
+++ b/tests/data/convert.js
@@ -40,7 +40,8 @@ $root.Message = (function() {
         this.int64Map = {};
         if (properties)
             for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                this[keys[i]] = properties[keys[i]];
+                if (properties[keys[i]] != null)
+                    this[keys[i]] = properties[keys[i]];
     }
 
     /**
diff --git a/tests/data/mapbox/vector_tile.js b/tests/data/mapbox/vector_tile.js
index c913f02ae..1fd603292 100644
--- a/tests/data/mapbox/vector_tile.js
+++ b/tests/data/mapbox/vector_tile.js
@@ -37,7 +37,8 @@ $root.vector_tile = (function() {
             this.layers = [];
             if (properties)
                 for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                    this[keys[i]] = properties[keys[i]];
+                    if (properties[keys[i]] != null)
+                        this[keys[i]] = properties[keys[i]];
         }
 
         /**
@@ -252,7 +253,8 @@ $root.vector_tile = (function() {
             function Value(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -587,7 +589,8 @@ $root.vector_tile = (function() {
                 this.geometry = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -911,7 +914,8 @@ $root.vector_tile = (function() {
                 this.values = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
diff --git a/tests/data/package.js b/tests/data/package.js
index 7edfb9e99..91a65371b 100644
--- a/tests/data/package.js
+++ b/tests/data/package.js
@@ -51,7 +51,8 @@ $root.Package = (function() {
         this.cliDependencies = [];
         if (properties)
             for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                this[keys[i]] = properties[keys[i]];
+                if (properties[keys[i]] != null)
+                    this[keys[i]] = properties[keys[i]];
     }
 
     /**
@@ -681,7 +682,8 @@ $root.Package = (function() {
         function Repository(properties) {
             if (properties)
                 for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                    this[keys[i]] = properties[keys[i]];
+                    if (properties[keys[i]] != null)
+                        this[keys[i]] = properties[keys[i]];
         }
 
         /**
diff --git a/tests/data/rpc-es6.js b/tests/data/rpc-es6.js
index 13af8275d..b258ac1a8 100644
--- a/tests/data/rpc-es6.js
+++ b/tests/data/rpc-es6.js
@@ -83,7 +83,8 @@ export const MyRequest = $root.MyRequest = (() => {
     function MyRequest(properties) {
         if (properties)
             for (let keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                this[keys[i]] = properties[keys[i]];
+                if (properties[keys[i]] != null)
+                    this[keys[i]] = properties[keys[i]];
     }
 
     /**
@@ -256,7 +257,8 @@ export const MyResponse = $root.MyResponse = (() => {
     function MyResponse(properties) {
         if (properties)
             for (let keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                this[keys[i]] = properties[keys[i]];
+                if (properties[keys[i]] != null)
+                    this[keys[i]] = properties[keys[i]];
     }
 
     /**
diff --git a/tests/data/rpc.js b/tests/data/rpc.js
index 6e8ff369c..8bda57ed5 100644
--- a/tests/data/rpc.js
+++ b/tests/data/rpc.js
@@ -85,7 +85,8 @@ $root.MyRequest = (function() {
     function MyRequest(properties) {
         if (properties)
             for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                this[keys[i]] = properties[keys[i]];
+                if (properties[keys[i]] != null)
+                    this[keys[i]] = properties[keys[i]];
     }
 
     /**
@@ -258,7 +259,8 @@ $root.MyResponse = (function() {
     function MyResponse(properties) {
         if (properties)
             for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                this[keys[i]] = properties[keys[i]];
+                if (properties[keys[i]] != null)
+                    this[keys[i]] = properties[keys[i]];
     }
 
     /**
diff --git a/tests/data/test.js b/tests/data/test.js
index 8d56c0acc..e97d0d84e 100644
--- a/tests/data/test.js
+++ b/tests/data/test.js
@@ -44,7 +44,8 @@ $root.jspb = (function() {
             function Empty(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -208,7 +209,8 @@ $root.jspb = (function() {
             function EnumContainer(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -397,7 +399,8 @@ $root.jspb = (function() {
                 this.aRepeatedString = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -627,7 +630,8 @@ $root.jspb = (function() {
                 this.aRepeatedString = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -838,7 +842,8 @@ $root.jspb = (function() {
             function SpecialCases(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -1075,7 +1080,8 @@ $root.jspb = (function() {
                 this.aRepeatedString = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -1364,7 +1370,8 @@ $root.jspb = (function() {
                 function Nested(properties) {
                     if (properties)
                         for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                            this[keys[i]] = properties[keys[i]];
+                            if (properties[keys[i]] != null)
+                                this[keys[i]] = properties[keys[i]];
                 }
 
                 /**
@@ -1550,7 +1557,8 @@ $root.jspb = (function() {
                 this[".jspb.test.IndirectExtension.repeatedSimple"] = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -1934,7 +1942,8 @@ $root.jspb = (function() {
                 this.aRepeatedString = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -2223,7 +2232,8 @@ $root.jspb = (function() {
                 function Nested(properties) {
                     if (properties)
                         for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                            this[keys[i]] = properties[keys[i]];
+                            if (properties[keys[i]] != null)
+                                this[keys[i]] = properties[keys[i]];
                 }
 
                 /**
@@ -2398,7 +2408,8 @@ $root.jspb = (function() {
             function OuterMessage(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -2544,7 +2555,8 @@ $root.jspb = (function() {
                 function Complex(properties) {
                     if (properties)
                         for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                            this[keys[i]] = properties[keys[i]];
+                            if (properties[keys[i]] != null)
+                                this[keys[i]] = properties[keys[i]];
                 }
 
                 /**
@@ -2720,7 +2732,8 @@ $root.jspb = (function() {
             function IsExtension(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -2892,7 +2905,8 @@ $root.jspb = (function() {
             function IndirectExtension(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -3046,7 +3060,8 @@ $root.jspb = (function() {
             function DefaultValues(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -3373,7 +3388,8 @@ $root.jspb = (function() {
                 this.repeatedDoubleField = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -3728,7 +3744,8 @@ $root.jspb = (function() {
                 this.simple2 = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -4031,7 +4048,8 @@ $root.jspb = (function() {
             function CloneExtension(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -4210,7 +4228,8 @@ $root.jspb = (function() {
                 this.repeatedGroup = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -4517,7 +4536,8 @@ $root.jspb = (function() {
                     this.someBool = [];
                     if (properties)
                         for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                            this[keys[i]] = properties[keys[i]];
+                            if (properties[keys[i]] != null)
+                                this[keys[i]] = properties[keys[i]];
                 }
 
                 /**
@@ -4732,7 +4752,8 @@ $root.jspb = (function() {
                 function RequiredGroup(properties) {
                     if (properties)
                         for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                            this[keys[i]] = properties[keys[i]];
+                            if (properties[keys[i]] != null)
+                                this[keys[i]] = properties[keys[i]];
                 }
 
                 /**
@@ -4907,7 +4928,8 @@ $root.jspb = (function() {
                 function OptionalGroup(properties) {
                     if (properties)
                         for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                            this[keys[i]] = properties[keys[i]];
+                            if (properties[keys[i]] != null)
+                                this[keys[i]] = properties[keys[i]];
                 }
 
                 /**
@@ -5085,7 +5107,8 @@ $root.jspb = (function() {
             function TestGroup1(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -5264,7 +5287,8 @@ $root.jspb = (function() {
             function TestReservedNames(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -5456,7 +5480,8 @@ $root.jspb = (function() {
             function TestReservedNamesExtension(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -5615,7 +5640,8 @@ $root.jspb = (function() {
                 this.repeatedField = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -6064,7 +6090,8 @@ $root.jspb = (function() {
             function TestEndsWithBytes(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -6282,7 +6309,8 @@ $root.jspb = (function() {
                 this.mapStringTestmapfields = {};
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -6950,7 +6978,8 @@ $root.jspb = (function() {
             function MapValueMessageNoBinary(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -7122,7 +7151,8 @@ $root.jspb = (function() {
             function Deeply(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -7267,7 +7297,8 @@ $root.jspb = (function() {
                 function Nested(properties) {
                     if (properties)
                         for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                            this[keys[i]] = properties[keys[i]];
+                            if (properties[keys[i]] != null)
+                                this[keys[i]] = properties[keys[i]];
                 }
 
                 /**
@@ -7413,7 +7444,8 @@ $root.jspb = (function() {
                     function Message(properties) {
                         if (properties)
                             for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                                this[keys[i]] = properties[keys[i]];
+                                if (properties[keys[i]] != null)
+                                    this[keys[i]] = properties[keys[i]];
                     }
 
                     /**
@@ -7617,7 +7649,8 @@ $root.google = (function() {
                 this.file = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -7828,7 +7861,8 @@ $root.google = (function() {
                 this.extension = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -8375,7 +8409,8 @@ $root.google = (function() {
                 this.reservedName = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -8880,7 +8915,8 @@ $root.google = (function() {
                 function ExtensionRange(properties) {
                     if (properties)
                         for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                            this[keys[i]] = properties[keys[i]];
+                            if (properties[keys[i]] != null)
+                                this[keys[i]] = properties[keys[i]];
                 }
 
                 /**
@@ -9074,7 +9110,8 @@ $root.google = (function() {
                 function ReservedRange(properties) {
                     if (properties)
                         for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                            this[keys[i]] = properties[keys[i]];
+                            if (properties[keys[i]] != null)
+                                this[keys[i]] = properties[keys[i]];
                 }
 
                 /**
@@ -9279,7 +9316,8 @@ $root.google = (function() {
             function FieldDescriptorProto(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -9805,7 +9843,8 @@ $root.google = (function() {
             function OneofDescriptorProto(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -10006,7 +10045,8 @@ $root.google = (function() {
                 this.value = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -10246,7 +10286,8 @@ $root.google = (function() {
             function EnumValueDescriptorProto(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -10466,7 +10507,8 @@ $root.google = (function() {
                 this.method = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -10709,7 +10751,8 @@ $root.google = (function() {
             function MethodDescriptorProto(properties) {
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -10998,7 +11041,8 @@ $root.google = (function() {
                 this.uninterpretedOption = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -11499,7 +11543,8 @@ $root.google = (function() {
                 this.uninterpretedOption = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -11777,7 +11822,8 @@ $root.google = (function() {
                 this.uninterpretedOption = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -12157,7 +12203,8 @@ $root.google = (function() {
                 this.uninterpretedOption = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -12354,7 +12401,8 @@ $root.google = (function() {
                 this.uninterpretedOption = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -12608,7 +12656,8 @@ $root.google = (function() {
                 this.uninterpretedOption = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -12823,7 +12872,8 @@ $root.google = (function() {
                 this.uninterpretedOption = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -13039,7 +13089,8 @@ $root.google = (function() {
                 this.uninterpretedOption = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -13314,7 +13365,8 @@ $root.google = (function() {
                 this.name = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -13652,7 +13704,8 @@ $root.google = (function() {
                 function NamePart(properties) {
                     if (properties)
                         for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                            this[keys[i]] = properties[keys[i]];
+                            if (properties[keys[i]] != null)
+                                this[keys[i]] = properties[keys[i]];
                 }
 
                 /**
@@ -13849,7 +13902,8 @@ $root.google = (function() {
                 this.location = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -14046,7 +14100,8 @@ $root.google = (function() {
                     this.leadingDetachedComments = [];
                     if (properties)
                         for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                            this[keys[i]] = properties[keys[i]];
+                            if (properties[keys[i]] != null)
+                                this[keys[i]] = properties[keys[i]];
                 }
 
                 /**
@@ -14363,7 +14418,8 @@ $root.google = (function() {
                 this.annotation = [];
                 if (properties)
                     for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                        this[keys[i]] = properties[keys[i]];
+                        if (properties[keys[i]] != null)
+                            this[keys[i]] = properties[keys[i]];
             }
 
             /**
@@ -14557,7 +14613,8 @@ $root.google = (function() {
                     this.path = [];
                     if (properties)
                         for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
-                            this[keys[i]] = properties[keys[i]];
+                            if (properties[keys[i]] != null)
+                                this[keys[i]] = properties[keys[i]];
                 }
 
                 /**