fix case where Request and init was supplied

sdk_contrib/fetch/lib/fetch_p.js

@@ -92,7 +92,7 @@ function enableCapture(baseFetchFunction, requestClass, downstreamXRayEnabled, s
     const thisDownstreamXRayEnabled = !!downstreamXRayEnabled;
     const thisSubsegmentCallback = subsegmentCallback;
     // Standardize request information
-    const request = args[0] instanceof requestClass ?
+    const request = (args[0] instanceof requestClass && args.length === 1) ?
       args[0] :
       new requestClass(...args);
 

sdk_contrib/fetch/test/unit/fetch_p.test.js

@@ -189,6 +189,48 @@ describe('Unit tests', function () {
       }
     });
 
+    it('transfers dispatcher property for undici with Request object', async function () {
+      const activeFetch = captureFetch(true);
+      const agent = new Agent({
+        maxSockets: 1234
+      });
+      await activeFetch(new Request('https://www.foo.com'), {
+        dispatcher: agent
+      });
+      stubFetch.should.have.been.calledOnceWith(sinon.match({ url: 'https://www.foo.com/' }));
+      stubResolveSegment.should.have.been.called;
+
+      // check if dispatcher was transferred
+      const dummyRequest = new Request('https://www.foo.com', {
+        dispatcher: agent
+      });
+      const dispatcherSymbol = Object.getOwnPropertySymbols(dummyRequest).find(symbol => symbol.description === 'dispatcher');
+      if (dispatcherSymbol) {
+        stubFetch.should.have.been.calledOnceWith(sinon.match({ [dispatcherSymbol]: agent }));
+      }
+    });
+
+    it('transfers dispatcher property for undici with url and init', async function () {
+      const activeFetch = captureFetch(true);
+      const agent = new Agent({
+        maxSockets: 1234
+      });
+      await activeFetch('https://www.foo.com', {
+        dispatcher: agent
+      });
+      stubFetch.should.have.been.calledOnceWith(sinon.match({ url: 'https://www.foo.com/' }));
+      stubResolveSegment.should.have.been.called;
+
+      // check if dispatcher was transferred
+      const dummyRequest = new Request('https://www.foo.com', {
+        dispatcher: agent
+      });
+      const dispatcherSymbol = Object.getOwnPropertySymbols(dummyRequest).find(symbol => symbol.description === 'dispatcher');
+      if (dispatcherSymbol) {
+        stubFetch.should.have.been.calledOnceWith(sinon.match({ [dispatcherSymbol]: agent }));
+      }
+    });
+
     it('calls base function when no parent and automatic mode', async function () {
       const activeFetch = captureFetch(true);
       stubResolveSegment.returns(null);