Fixes for nullable selection (VE core)

gistfile1.diff

diff --git a/modules/ve/dm/ve.dm.Surface.js b/modules/ve/dm/ve.dm.Surface.js
index 6e07f70..8ecd560 100644
--- a/modules/ve/dm/ve.dm.Surface.js
+++ b/modules/ve/dm/ve.dm.Surface.js
@@ -525,7 +525,7 @@ ve.dm.Surface.prototype.changeInternal = function ( transactions, selection, ski
                ( !selectionBefore || !selectionBefore.equals( selectionAfter ) ) &&
                ( selectionAfter && selectionAfter.equals( this.selection ) )
        ) {
-               this.emit( 'select', this.selection.clone() );
+               this.emit( 'select', this.selection && this.selection.clone() );
        }
 
        if ( contextChange ) {
@@ -549,8 +549,8 @@ ve.dm.Surface.prototype.breakpoint = function () {
        if ( this.newTransactions.length > 0 ) {
                this.undoStack.push( {
                        'transactions': this.newTransactions,
-                       'selection': this.selection.clone(),
-                       'selectionBefore': this.selectionBefore.clone()
+                       'selection': this.selection && this.selection.clone(),
+                       'selectionBefore': this.selectionBefore && this.selectionBefore.clone()
                } );
                this.newTransactions = [];
                this.emit( 'history' );