Fix broken protocol in MISCONF error, RM_Yield bugs, RM_Call(EVAL) OOM check bug, and new RM_Call checks. (#10786)

* Fix broken protocol when redis can't persist to RDB (general commands, not
  modules), excessive newline. regression of #10372 (7.0 RC3)
* Fix broken protocol when Redis can't persist to AOF (modules and
  scripts), missing newline.
* Fix bug in OOM check of EVAL scripts called from RM_Call.
  set the cached OOM state for scripts before executing module commands too,
  so that it can serve scripts that are executed by modules.
  i.e. in the past EVAL executed by RM_Call could have either falsely
  fail or falsely succeeded because of a wrong cached OOM state flag.
* Fix bugs with RM_Yield:
  1. SHUTDOWN should only accept the NOSAVE mode
  2. Avoid eviction during yield command processing.
  3. Avoid processing master client commands while yielding from another client
* Add new two more checks to RM_Call script mode.
  1. READONLY You can't write against a read only replica
  2. MASTERDOWN Link with MASTER is down and `replica-serve-stale-data` is set to `no`
* Add new RM_Call flag to let redis automatically refuse `deny-oom` commands
  while over the memory limit. 
* Add tests to cover various errors from Scripts, Modules, Modules
  calling scripts, and Modules calling commands in script mode.

Add tests:
* Looks like the MISCONF error was completely uncovered by the tests,
  add tests for it, including from scripts, and modules
* Add tests for NOREPLICAS from scripts
* Add tests for the various errors in module RM_Call, including RM_Call that
  calls EVAL, and RM_call in "eval mode". that includes:
  NOREPLICAS, READONLY, MASTERDOWN, MISCONF

1 files changed, 48 insertions, 0 deletions

diff --git a/tests/modules/misc.c b/tests/modules/misc.c
index db9c090d4..da6ee9f9e 100644
--- a/tests/modules/misc.c
+++ b/tests/modules/misc.c
@@ -310,6 +310,50 @@ int test_monotonic_time(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
     return REDISMODULE_OK;
 }
 
+/* wrapper for RM_Call */
+int test_rm_call(RedisModuleCtx *ctx, RedisModuleString **argv, int argc){
+    if(argc < 2){
+        return RedisModule_WrongArity(ctx);
+    }
+
+    const char* cmd = RedisModule_StringPtrLen(argv[1], NULL);
+
+    RedisModuleCallReply* rep = RedisModule_Call(ctx, cmd, "Ev", argv + 2, argc - 2);
+    if(!rep){
+        RedisModule_ReplyWithError(ctx, "NULL reply returned");
+    }else{
+        RedisModule_ReplyWithCallReply(ctx, rep);
+        RedisModule_FreeCallReply(rep);
+    }
+
+    return REDISMODULE_OK;
+}
+
+/* wrapper for RM_Call with flags */
+int test_rm_call_flags(RedisModuleCtx *ctx, RedisModuleString **argv, int argc){
+    if(argc < 3){
+        return RedisModule_WrongArity(ctx);
+    }
+
+    /* Append Ev to the provided flags. */
+    RedisModuleString *flags = RedisModule_CreateStringFromString(ctx, argv[1]);
+    RedisModule_StringAppendBuffer(ctx, flags, "Ev", 2);
+
+    const char* flg = RedisModule_StringPtrLen(flags, NULL);
+    const char* cmd = RedisModule_StringPtrLen(argv[2], NULL);
+
+    RedisModuleCallReply* rep = RedisModule_Call(ctx, cmd, flg, argv + 3, argc - 3);
+    if(!rep){
+        RedisModule_ReplyWithError(ctx, "NULL reply returned");
+    }else{
+        RedisModule_ReplyWithCallReply(ctx, rep);
+        RedisModule_FreeCallReply(rep);
+    }
+    RedisModule_FreeString(ctx, flags);
+
+    return REDISMODULE_OK;
+}
+
 int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
     REDISMODULE_NOT_USED(argv);
     REDISMODULE_NOT_USED(argc);
@@ -351,6 +395,10 @@ int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
         return REDISMODULE_ERR;
     if (RedisModule_CreateCommand(ctx,"test.monotonic_time", test_monotonic_time,"",0,0,0) == REDISMODULE_ERR)
         return REDISMODULE_ERR;
+    if (RedisModule_CreateCommand(ctx, "test.rm_call", test_rm_call,"allow-stale", 0, 0, 0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+    if (RedisModule_CreateCommand(ctx, "test.rm_call_flags", test_rm_call_flags,"allow-stale", 0, 0, 0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
 
     return REDISMODULE_OK;
 }