Preserve continuation URL on OAuth2 error redirect

Use the ContinueURL from the state token so the user is redirected
back to where they initiated the flow instead of the root URL.
The redirect is safe because safeRedirect validates the host.

Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>

pkg/server/api/console/v1/resolver.go

@@ -268,9 +268,15 @@ func handleConnectorOAuth2Error(
 	oauthErrDesc := query.Get("error_description")
 
 	provider := "unknown"
+	redirectURL := baseURL.String()
 	if stateToken := query.Get("state"); stateToken != "" {
-		if p, err := connector.ExtractProviderFromState(stateToken); err == nil {
-			provider = p
+		if payload, err := connector.DecodeOAuth2StatePayload(stateToken); err == nil {
+			if payload.Data.Provider != "" {
+				provider = payload.Data.Provider
+			}
+			if payload.Data.ContinueURL != "" {
+				redirectURL = payload.Data.ContinueURL
+			}
 		}
 	}
 
@@ -280,7 +286,7 @@ func handleConnectorOAuth2Error(
 		log.String("error_description", oauthErrDesc),
 	)
 
-	parsedURL, _ := url.Parse(baseURL.String())
+	parsedURL, _ := url.Parse(redirectURL)
 	q := parsedURL.Query()
 	q.Set("error", oauthErr)
 	if oauthErrDesc != "" {