Fix for infinite recursion in ReDoc 2.0.0-alpha.4

Schema.ts.patch

diff --git a/src/services/models/Schema.ts b/src/services/models/Schema.ts
index c53219e..20cbabf 100644
--- a/src/services/models/Schema.ts
+++ b/src/services/models/Schema.ts
@@ -67,11 +67,13 @@ export class SchemaModel {
     this.schema = parser.mergeAllOf(this.rawSchema, this._$ref, isChild);
     this.init(parser, isChild);
 
-    parser.exitRef(schemaOrRef);
+    if (!this.isCircular) {
+      parser.exitRef(schemaOrRef);
 
-    for (let $ref of this.schema.namedParents || []) {
-      // exit all the refs visited during allOf traverse
-      parser.exitRef({ $ref });
+      for (let $ref of this.schema.namedParents || []) {
+        // exit all the refs visited during allOf traverse
+        parser.exitRef({ $ref });
+      }
     }
   }