Fix Node._findSchema bug when path is not present in schema

Previously, the function would return the wrong schema when it was
unable to find a path in the given schema.

src/js/Node.js

@@ -2634,11 +2634,15 @@ Node._findSchema = function (schema, schemaRefs, path) {
         }
       }
       else if (typeof key === 'string' && childSchema.properties) {
-        childSchema = childSchema.properties[key] || null;
+        if (!(key in childSchema.properties)) {
+          foundSchema = null;
+        } else {
+          childSchema = childSchema.properties[key];
           if (childSchema) {
             foundSchema = Node._findSchema(childSchema, schemaRefs, nextPath);
           }
         }
+      }
       else if (typeof key === 'number' && childSchema.items) {
         childSchema = childSchema.items;
         if (childSchema) {
@@ -2648,6 +2652,12 @@ Node._findSchema = function (schema, schemaRefs, path) {
     }
 
   }
+
+  // If the found schema is the input schema, the schema does not have the given path
+  if (foundSchema === schema && path.length > 0) {
+    return null;
+  }
+
   return foundSchema
 };
 

test/Node.test.js

@@ -59,6 +59,26 @@ describe('Node', function () {
             );
         });
 
+        it('should return null for path that has no schema', function () {
+            var schema = {
+                type: 'object',
+                properties: {
+                    foo: {
+                        type: 'object',
+                        properties: {
+                            baz: {
+                                type: 'number'
+                            }
+                        }
+                    }
+                }
+            };
+            var path = ['bar'];
+            assert.strictEqual(Node._findSchema(schema, {}, path), null);
+            path = ['foo', 'bar'];
+            assert.strictEqual(Node._findSchema(schema, {}, path), null);
+        });
+
         describe('with $ref', function () {
             it('should find a referenced schema', function () {
                 var schema = {
@@ -212,6 +232,36 @@ describe('Node', function () {
                     'second pattern property child'
                 );
             });
+
+            it('should return null for path that has no schema', function () {
+                var schema = {
+                    type: 'object',
+                    properties: {
+                        levelTwo: {
+                            type: 'object',
+                            properties: {
+                                levelThree: {
+                                    type: 'number'
+                                }
+                            }
+                        }
+                    },
+                    patternProperties: {
+                        '^foo[0-9]': {
+                            title: 'foo[0-9] pattern property',
+                            type: 'string'
+                        },
+                        '^bar[0-9]': {
+                            title: 'bar[0-9] pattern property',
+                            type: 'string'
+                        }
+                    }
+                };
+                var path = ['not-in-schema'];
+                assert.strictEqual(Node._findSchema(schema, {}, path), null);
+                path = ['levelOne', 'not-in-schema'];
+                assert.strictEqual(Node._findSchema(schema, {}, path), null);
+            });
         });
     });
 });