Various reference fixes

3 files changed, 9 insertions, 7 deletions

diff --git a/src/doc.js b/src/doc.js
index 54b7c70..1a025f3 100755
--- a/src/doc.js
+++ b/src/doc.js
@@ -15,10 +15,11 @@ SVG.Doc = SVG.invent({
       element.appendChild(this.node)
     }
     
-    /* set svg element attributes */
+    /* set svg element attributes and ensure defs node */
     this
       .attr({ xmlns: SVG.ns, version: '1.1', width: '100%', height: '100%' })
       .attr('xmlns:xlink', SVG.xlink, SVG.xmlns)
+      .defs()
   }
 
   // Inherit from
diff --git a/src/parent.js b/src/parent.js
index 55878ec..095120a 100755
--- a/src/parent.js
+++ b/src/parent.js
@@ -18,10 +18,10 @@ SVG.Parent = SVG.invent({
     // Add given element at a position
   , add: function(element, i) {
       if (!this.has(element)) {
-        /* define insertion index if none given */
+        // Define insertion index if none given
         i = i == null ? this.children().length : i
         
-        /* add element references */
+        // Add element references
         this.node.insertBefore(element.node, this.node.childNodes[i] || null)
       }
 
@@ -78,9 +78,10 @@ SVG.Parent = SVG.invent({
       // Remove children
       while(this.node.hasChildNodes())
         this.node.removeChild(this.node.lastChild)
-
-      // Remove defs cache reference
-      delete this._defs
+      
+      // Ensure new defs node
+      if (this instanceof SVG.Doc)
+        this.defs()
 
       return this
     }
diff --git a/src/rbox.js b/src/rbox.js
index 598b3b4..fe6a9fa 100755
--- a/src/rbox.js
+++ b/src/rbox.js
@@ -31,7 +31,7 @@ SVG.RBox = function(element) {
     
     /* calculate cumulative zoom from svg documents */
     e = element
-    while (e = e.parent()) {
+    while (e.parent && (e = e.parent())) {
       if (e.type == 'svg' && e.viewbox) {
         zoom *= e.viewbox().zoom
         this.x -= e.x() || 0