null check first in r.expr()

Author: marshall007

lib/term.js

@@ -2165,7 +2165,10 @@ Term.prototype.expr = function(expression, nestingLevel) {
     //if (nestingLevel == null) nestingLevel = self._r.nestingLevel;
     if (_nestingLevel < 0) throw new Error.ReqlDriverError('Nesting depth limit exceeded.\nYou probably have a circular reference somewhere')
 
-    if (expression instanceof Term || expression.__proxy) {
+    if (expression === null) {
+        return new Term(self._r, null, expression);
+    }
+    else if (expression instanceof Term || expression.__proxy) {
         return expression;
     }
     else if (expression instanceof Function) {
@@ -2198,10 +2201,7 @@ Term.prototype.expr = function(expression, nestingLevel) {
         return new Term(self._r, null, optArgs);
     }
     else { // Primitive
-        if (expression === null) {
-            return new Term(self._r, null, expression);
-        }
-        else if (typeof expression === 'string') {
+        if (typeof expression === 'string') {
             // RethinkDB doesn't support the null character.
             if (/\00/.test(expression)) {
                 self._error = new Error.ReqlDriverError('The null character is currently not supported by RethinkDB');