web/flows: fix RedirectStage not detecting absolute URLs correctly (#…

…5781)

* web: getURL() method in RedirectStage.ts now actually detects URLs (#5732)

Signed-off-by: Saeverix <1863379+Saeverix@users.noreply.github.com>

* use native API to build full URL

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

---------

Signed-off-by: Saeverix <1863379+Saeverix@users.noreply.github.com>
Signed-off-by: Jens Langhammer <jens@goauthentik.io>
Co-authored-by: Jens Langhammer <jens@goauthentik.io>

web/src/flow/stages/RedirectStage.ts

@@ -39,10 +39,7 @@ export class RedirectStage extends BaseStage<RedirectChallenge, FlowChallengeRes
     }
 
     getURL(): string {
-        if (!this.challenge.to.includes("://")) {
-            return window.location.origin + this.challenge.to;
-        }
-        return this.challenge.to;
+        return new URL(this.challenge.to, document.baseURI).toString();
     }
 
     firstUpdated(): void {