When the pool change the diff. Abort current mining and startover.

ccminer.cpp

@@ -1202,6 +1202,7 @@ static void *miner_thread(void *userdata)
 	bool extrajob = false;
 	char s[16];
 	int rc = 0;
+	scan_abort_flag = false;
 
 	memset(&work, 0, sizeof(work)); // prevent work from being used uninitialized
 
@@ -1813,7 +1814,8 @@ static void *longpoll_thread(void *userdata)
 				json_decref(val);
 			goto out;
 		}
-		if (likely(val)) {
+		if (likely(val)) 
+		{
 			if (!opt_quiet) applog(LOG_INFO, "LONGPOLL detected new block");
 			soval = json_object_get(json_object_get(val, "result"), "submitold");
 			submit_old = soval ? json_is_true(soval) : false;

util.cpp

@@ -1208,7 +1208,9 @@ static bool stratum_set_difficulty(struct stratum_ctx *sctx, json_t *params)
 	pthread_mutex_unlock(&sctx->work_lock);
 
 	/* store for api stats */
-	if (diff != global_diff) {
+	if (diff != global_diff) 
+	{
+		scan_abort_flag = true;
 		global_diff = diff;
 		applog(LOG_WARNING, "Stratum difficulty set to %g", diff);
 	}