make copyDatabase use admin db automatically SERVER-222

jstests/copydb.js

@@ -0,0 +1,20 @@
+
+
+
+
+a = db.getSisterDB( "copydb-test-a" );
+b = db.getSisterDB( "copydb-test-b" );
+
+a.dropDatabase();
+b.dropDatabase();
+
+a.foo.save( { a : 1 } );
+
+assert.eq( 1 , a.foo.count() , "A" );
+assert.eq( 0 , b.foo.count() , "B" );
+
+a.copyDatabase( a._name , b._name );
+
+assert.eq( 1 , a.foo.count() , "C" );
+assert.eq( 1 , b.foo.count() , "D" );
+

shell/db.js

@@ -42,6 +42,12 @@ DB.prototype.runCommand = function( obj ){
 
 DB.prototype._dbCommand = DB.prototype.runCommand;
 
+DB.prototype._adminCommand = function( obj ){
+    if ( this._name == "admin" )
+        return this.runCommand( obj );
+    return this.getSisterDB( "admin" ).runCommand( obj );
+}
+
 DB.prototype.addUser = function( username , pass ){
     var c = this.getCollection( "system.users" );
 
@@ -216,7 +222,7 @@ DB.prototype.copyDatabase = function(fromdb, todb, fromhost) {
     assert( isString(todb) && todb.length );
     fromhost = fromhost || "";
     //this.resetIndexCache();
-    return this._dbCommand( { copydb:1, fromhost:fromhost, fromdb:fromdb, todb:todb } );
+    return this._adminCommand( { copydb:1, fromhost:fromhost, fromdb:fromdb, todb:todb } );
 }
 
 /**