redis-check-rdb add when_opcode check for module aux (#10859)

In #9199, we add a `goto eoferr` in when_opcode check,
this means that if the when_opcode check fails, we will
abort the rdb loading, but this not reflected in the
rdb-check tool. So someone can modify when_opcode to make
rdb load fail, but rdb-check will report OK. Just a cleanup
or a code consistency issue.
```
serverLog: # Internal error in RDB reading offset 0, function at rdb.c:3055 -> bad when_opcode
[offset 0] Checking RDB file dump.rdb
[offset 109] \o/ RDB looks OK! \o/
```

Plus a minor memory leak fix like #9860, note that it will
exit immediately after the eoferr, so it is not strictly a
leak, so it is also a small cleanup.

1 files changed, 8 insertions, 1 deletions

diff --git a/src/redis-check-rdb.c b/src/redis-check-rdb.c
index accdc35b0..959768991 100644
--- a/src/redis-check-rdb.c
+++ b/src/redis-check-rdb.c
@@ -283,7 +283,10 @@ int redis_check_rdb(char *rdbfilename, FILE *fp) {
             robj *auxkey, *auxval;
             rdbstate.doing = RDB_CHECK_DOING_READ_AUX;
             if ((auxkey = rdbLoadStringObject(&rdb)) == NULL) goto eoferr;
-            if ((auxval = rdbLoadStringObject(&rdb)) == NULL) goto eoferr;
+            if ((auxval = rdbLoadStringObject(&rdb)) == NULL) {
+                decrRefCount(auxkey);
+                goto eoferr;
+            }
 
             rdbCheckInfo("AUX FIELD %s = '%s'",
                 (char*)auxkey->ptr, (char*)auxval->ptr);
@@ -297,6 +300,10 @@ int redis_check_rdb(char *rdbfilename, FILE *fp) {
             if ((moduleid = rdbLoadLen(&rdb,NULL)) == RDB_LENERR) goto eoferr;
             if ((when_opcode = rdbLoadLen(&rdb,NULL)) == RDB_LENERR) goto eoferr;
             if ((when = rdbLoadLen(&rdb,NULL)) == RDB_LENERR) goto eoferr;
+            if (when_opcode != RDB_MODULE_OPCODE_UINT) {
+                rdbCheckError("bad when_opcode");
+                goto err;
+            }
 
             char name[10];
             moduleTypeNameByID(name,moduleid);