Handle empty hash when all fields are expired during RDB load

Signed-off-by: Hanxi Zhang <hanxizh@amazon.com>

Author: hanxizh9910

src/rdb.c

@@ -2283,6 +2283,12 @@ robj *rdbLoadObject(int rdbtype, rio *rdb, sds key, int dbid, int *error, int rd
 
         /* All pairs should be read by now */
         serverAssert(len == 0);
+
+        /* Check if hash became empty after skipping all expired fields */
+        if (hashTypeLength(o) == 0) {
+            decrRefCount(o);
+            goto emptykey;
+        }
     } else if (rdbtype == RDB_TYPE_LIST_QUICKLIST || rdbtype == RDB_TYPE_LIST_QUICKLIST_2) {
         if ((len = rdbLoadLen(rdb, NULL)) == RDB_LENERR) return NULL;
         if (len == 0) goto emptykey;

tests/unit/hashexpire.tcl

@@ -4616,6 +4616,36 @@ start_server {tags {"hashexpire skip expired fields"}} {
         assert_equal "" [r HGET myhash f3]
     } {} {needs:debug}
 
+    test {Hash is skipped when all fields are expired during RDB load on primary} {
+        r FLUSHALL
+        
+        # Disable active expiration
+        r DEBUG SET-ACTIVE-EXPIRE 0
+        r HSETEX myhash PX 1 FIELDS 3 f1 v1 f2 v2 f3 v3
+        
+        # No permanent field - all fields will expire
+        
+        # Wait until all fields are expired (HTTL returns -2)
+        wait_for_condition 50 100 {
+            [lindex [r HTTL myhash FIELDS 1 f1] 0] == -2 &&
+            [lindex [r HTTL myhash FIELDS 1 f2] 0] == -2 &&
+            [lindex [r HTTL myhash FIELDS 1 f3] 0] == -2
+        } else {
+            fail "Fields did not expire"
+        }
+        
+        r SAVE
+        r FLUSHALL
+        r DEBUG RELOAD NOSAVE
+        
+        # Re-enable active expiration
+        r DEBUG SET-ACTIVE-EXPIRE 1
+        
+        # Verify: key should not exist at all (empty hash skipped)
+        assert_equal 0 [r EXISTS myhash]
+        assert_equal 0 [r HLEN myhash]
+    } {} {needs:debug}
+
     test {RESTORE loads expired hash fields} {
         r FLUSHALL
         r DEBUG SET-ACTIVE-EXPIRE 0