Index: trunk/src/org/openstreetmap/josm/data/oauth/SignpostAdapters.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/oauth/SignpostAdapters.java	(revision 15221)
+++ trunk/src/org/openstreetmap/josm/data/oauth/SignpostAdapters.java	(revision 15222)
@@ -40,5 +40,5 @@
         @Override
         protected HttpRequest createRequest(String endpointUrl) throws Exception {
-            return new HttpRequest(HttpClient.create(new URL(endpointUrl), "GET"));
+            return new HttpRequest(HttpClient.create(new URL(endpointUrl)));
         }
 
Index: trunk/src/org/openstreetmap/josm/gui/MainApplication.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/MainApplication.java	(revision 15221)
+++ trunk/src/org/openstreetmap/josm/gui/MainApplication.java	(revision 15222)
@@ -997,4 +997,6 @@
             Utils.updateSystemProperty("jsse.enableSNIExtension", "false");
         }
+        // Disable automatic POST retry after 5 minutes, see #17882 / https://bugs.openjdk.java.net/browse/JDK-6382788
+        Utils.updateSystemProperty("sun.net.http.retryPost", "false");
     }