TT#63000 fix SSCAN using empty key name

Change-Id: Ifd294f135e6f05ab0b356d4ca0de6adde54bf777
(cherry picked from commit c182f411d8)

debian/patches/series

@@ -60,3 +60,4 @@ upstream/ndb_redis-set-message-level-to-debug-on-exec.patch
 sipwise/db_redis_skip_empty_keys.patch
 sipwise/db_redis_graceful_scan.patch
 sipwise/db_redis_sscan.patch
+sipwise/db_redis_sscan_fix_empty_key.patch

debian/patches/sipwise/db_redis_sscan_fix_empty_key.patch

@@ -0,0 +1,11 @@
+--- a/src/modules/db_redis/redis_dbase.c
++++ b/src/modules/db_redis/redis_dbase.c
+@@ -784,7 +784,7 @@
+     do {
+         snprintf(cursor_str, sizeof(cursor_str), "%lu", cursor);
+ 
+-        if (!index_key) {
++        if (!index_key || !index_key->len) {
+             if (db_redis_key_add_string(&query_v, "SCAN", 4) != 0) {
+                 LM_ERR("Failed to add scan command to scan query\n");
+                 goto err;