UX: minimal fix for https://github.com/pietervdvn/MapComplete/issues/2284

src/land.ts

@@ -1,16 +1,22 @@
+import { QueryParameters } from "./Logic/Web/QueryParameters"
 import { OsmConnection } from "./Logic/Osm/OsmConnection"
-import Constants from "./Models/Constants"
+import { LocalStorageSource } from "./Logic/Web/LocalStorageSource"
 
 console.log("Authorizing...")
-const key = Constants.osmAuthConfig.url + "oauth2_state"
-const st = window.localStorage.getItem(key)
-console.log("Prev state is", key, st)
-new OsmConnection().finishLogin((previousURL) => {
-    const fallback = window.location.protocol + "//" + window.location.host + "/index.html"
-    previousURL ??= fallback
-    if (previousURL.indexOf("/land") > 0) {
-        previousURL = fallback
-    }
-    console.log("Redirecting to", previousURL)
-    window.location.href = previousURL
-})
+
+if (QueryParameters.wasInitialized("error")) {
+// error=access_denied&error_description=The+resource+owner+or+authorization+server+denied+the+request.
+    alert("Access was denied")
+    const previousLocation = LocalStorageSource.get("location_before_login")
+    window.location.href = previousLocation.data ?? "./"
+} else {
+    new OsmConnection().finishLogin((previousURL) => {
+        const fallback = window.location.protocol + "//" + window.location.host + "/index.html"
+        previousURL ??= fallback
+        if (previousURL.indexOf("/land") > 0) {
+            previousURL = fallback
+        }
+        console.log("Redirecting to", previousURL)
+        window.location.href = previousURL
+    })
+}