[Tarantool-patches] [PATCH luajit 3/3] sysprof: fix a message with stop without run

[Sergey Bronnikov via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

When sysprof is not started the function `misc.sysprof.stop()`
reports that the profiler is already running:

| $ ./src/luajit -e 'print(misc.sysprof.stop())'
| nil     profiler is running already     22

The patch fixes that:

| $ ./src/luajit -e 'print(misc.sysprof.stop())'
| nil     profiler is not running         22

Follows up tarantool/tarantool#781
---
 src/lib_misc.c                                              | 6 ++++++
 .../tarantool-tests/profilers/misclib-sysprof-lapi.test.lua | 5 +++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/lib_misc.c b/src/lib_misc.c
index 1c81fd80..88ae9e10 100644
--- a/src/lib_misc.c
+++ b/src/lib_misc.c
@@ -336,6 +336,12 @@ LJLIB_CF(misc_sysprof_stop)
   return prof_error(L, PROFILE_ERRUSE, err_details);
 #else
   int status = luaM_sysprof_stop(L);
+  if (LJ_UNLIKELY(status == PROFILE_ERRRUN)) {
+      lua_pushnil(L);
+      lua_pushstring(L, err2msg(LJ_ERR_PROF_NOTRUNNING));
+      lua_pushinteger(L, EINVAL);
+      return 3;
+  }
   if (LJ_UNLIKELY(status != PROFILE_SUCCESS))
     return prof_error(L, status, NULL);
 
diff --git a/test/tarantool-tests/profilers/misclib-sysprof-lapi.test.lua b/test/tarantool-tests/profilers/misclib-sysprof-lapi.test.lua
index 91ea461b..f316c390 100644
--- a/test/tarantool-tests/profilers/misclib-sysprof-lapi.test.lua
+++ b/test/tarantool-tests/profilers/misclib-sysprof-lapi.test.lua
@@ -10,7 +10,7 @@ local test = tap.test("misclib-sysprof-lapi"):skipcond({
   ["Disabled due to #10803"] = os.getenv("LUAJIT_TEST_USE_VALGRIND"),
 })
 
-test:plan(43)
+test:plan(44)
 
 jit.off()
 -- XXX: Run JIT tuning functions in a safe frame to avoid errors
@@ -123,7 +123,8 @@ assert(res, err)
 
 -- Not running.
 res, err, errno = misc.sysprof.stop()
-test:ok(res == nil and err, "result status and error with not running")
+test:is(res, nil, "result status with not running")
+test:ok(err:match("profiler is not running"), "error with not running")
 test:ok(type(errno) == "number", "errno with not running")
 
 -- Bad path.
-- 
2.43.0