diff --git a/uppsrc/Core/InVector.h b/uppsrc/Core/InVector.h
index 5b9243144..ce0719a70 100644
--- a/uppsrc/Core/InVector.h
+++ b/uppsrc/Core/InVector.h
@@ -39,7 +39,7 @@ private:
 	uint16 slave;
 
 	InVectorSlave__ *Slave()          { return (InVectorSlave__ *)((byte *)this + slave); }
-	void SetSlave(InVectorSlave__ *s) { slave = (byte *)s - (byte *)this; }
+	void SetSlave(InVectorSlave__ *s) { slave = (uint16)((byte *)s - (byte *)this); }
 
 	void SetCache(int blki, int offset) const;
 	void ClearCache() const;
diff --git a/uppsrc/Core/XML.cpp b/uppsrc/Core/XML.cpp
index a1adc4f84..8dcf2a0a6 100644
--- a/uppsrc/Core/XML.cpp
+++ b/uppsrc/Core/XML.cpp
@@ -739,17 +739,31 @@ int  XmlNode::AttrInt(const char *id, int def) const
 	return p.IsInt() ? p.ReadInt() : def;
 }
 
+XmlNode& XmlNode::SetAttr(const char *id, const String& text)
+{
+	if(!attr)
+		attr.Create();
+	attr->GetAdd(id) = text;
+	return *this;
+}
+
+void XmlNode::SetAttrsPick(pick_ VectorMap<String, String>& a)
+{
+	if(a.GetCount() == 0)
+		attr.Clear();
+	else {
+		if(!attr)
+			attr.Create();
+		*attr = a;
+	}
+}
+
 XmlNode& XmlNode::SetAttr(const char *id, int i)
 {
 	SetAttr(id, AsString(i));
 	return *this;
 }
 
-XmlNode& XmlNode::SetAttr(const char *id, const String& text)
-{
-	attr.GetAdd(id) = text;
-	return *this;
-}
 
 bool Ignore(XmlParser& p, dword style)
 {
diff --git a/uppsrc/Core/XML.h b/uppsrc/Core/XML.h
index d00b7cfb5..6da8f095c 100644
--- a/uppsrc/Core/XML.h
+++ b/uppsrc/Core/XML.h
@@ -134,10 +134,10 @@ public:
 };
 
 class XmlNode {
-	int                       type;
-	String                    text;
-	VectorMap<String, String> attr;
-	Array<XmlNode>            node;
+	int                              type;
+	String                           text;
+	Array<XmlNode>                   node;
+	One< VectorMap<String, String> > attr;
 
 public:
 	static const XmlNode& Void();
@@ -176,15 +176,15 @@ public:
 	String         GatherText() const;
 	String         operator~() const                          { return GatherText(); }
 
-	int            GetAttrCount() const                       { return attr.GetCount(); }
-	String         AttrId(int i) const                        { return attr.GetKey(i); }
-	String         Attr(int i) const                          { return attr[i]; }
-	String         Attr(const char *id) const                 { return attr.Get(id, Null); }
+	int            GetAttrCount() const                       { return attr ? attr->GetCount() : 0; }
+	String         AttrId(int i) const                        { return attr->GetKey(i); }
+	String         Attr(int i) const                          { return (*attr)[i]; }
+	String         Attr(const char *id) const                 { return attr ? attr->Get(id, Null) : String(); }
 	XmlNode&       SetAttr(const char *id, const String& val);
 	int            AttrInt(const char *id, int def = Null) const;
 	XmlNode&       SetAttr(const char *id, int val);
 
-	void           SetAttrsPick(pick_ VectorMap<String, String>& a) { attr = a; }
+	void           SetAttrsPick(pick_ VectorMap<String, String>& a);
 
 	XmlNode()      { type = XML_DOC; }
 };