Allow passing depths to _child

lib/handlebars/compiler/compiler.js

@@ -426,11 +426,11 @@ export function compile(input, options, env) {
     }
     return compiled._setup(options);
   };
-  ret._child = function(i) {
+  ret._child = function(i, data, depths) {
     if (!compiled) {
       compiled = compileInput();
     }
-    return compiled._child(i);
+    return compiled._child(i, data, depths);
   };
   return ret;
 }

lib/handlebars/runtime.js

@@ -149,12 +149,12 @@ export function template(templateSpec, env) {
     }
   };
 
-  ret._child = function(i) {
-    if (templateSpec.useDepths) {
-      throw new Exception('_child can not be used with depthed templates');
+  ret._child = function(i, data, depths) {
+    if (templateSpec.useDepths && !depths) {
+      throw new Exception('must pass parent depths');
     }
 
-    return program(container, i, templateSpec[i]);
+    return program(container, i, templateSpec[i], data, depths);
   };
   return ret;
 }

spec/runtime.js

@@ -39,18 +39,25 @@ describe('runtime', function() {
       return;
     }
 
-    it('should throw for depthed methods', function() {
+    it('should throw for depthed methods without depths', function() {
       shouldThrow(function() {
         var template = Handlebars.compile('{{#foo}}{{../bar}}{{/foo}}');
+        // Calling twice to hit the non-compiled case.
         template._setup({});
         template._setup({});
         template._child(1);
-      }, Error, '_child can not be used with depthed templates');
+      }, Error, 'must pass parent depths');
     });
     it('should expose child template', function() {
       var template = Handlebars.compile('{{#foo}}bar{{/foo}}');
+        // Calling twice to hit the non-compiled case.
       equal(template._child(1)(), 'bar');
       equal(template._child(1)(), 'bar');
     });
+    it('should render depthed content', function() {
+      var template = Handlebars.compile('{{#foo}}{{../bar}}{{/foo}}');
+        // Calling twice to hit the non-compiled case.
+      equal(template._child(1, undefined, [{bar: 'baz'}])(), 'baz');
+    });
   });
 });