Looks good for me, thanks

On Saturday, February 23, 2019 4:34:42 PM MSK Cyrill Gorcunov wrote:
> If I create a new fiber and the join to himself we get an abort:
>  | tarantool> f = require('fiber')
>  | ---
>  | ...
>  | 
>  | tarantool> f.join(f.self())
>  | tarantool: src/fiber.c:407: fiber_join: Assertion `fiber->flags &
>  | FIBER_IS_JOINABLE' failed. Aborted (core dumped)
> 
> we should better throw an error.
> 
> v2: by georgy@
>  - add a testcase
> 
> Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
> ---
>  src/lua/fiber.c         |    6 +++++-
>  test/app/fiber.result   |   11 +++++++++++
>  test/app/fiber.test.lua |    7 +++++++
>  3 files changed, 23 insertions(+), 1 deletion(-)
> 
> Index: tarantool.git/src/lua/fiber.c
> ===================================================================
> --- tarantool.git.orig/src/lua/fiber.c
> +++ tarantool.git/src/lua/fiber.c
> @@ -676,10 +676,14 @@ lbox_fiber_join(struct lua_State *L)
>  {
>  	struct fiber *fiber = lbox_checkfiber(L, 1);
>  	struct lua_State *child_L = fiber->storage.lua.stack;
> -	fiber_join(fiber);
>  	struct error *e = NULL;
>  	int num_ret = 0;
>  	int coro_ref = 0;
> +
> +	if (!(fiber->flags & FIBER_IS_JOINABLE))
> +		luaL_error(L, "the fiber is not joinable");
> +	fiber_join(fiber);
> +
>  	if (child_L != NULL) {
>  		coro_ref = lua_tointeger(child_L, -1);
>  		lua_pop(child_L, 1);
> Index: tarantool.git/test/app/fiber.result
> ===================================================================
> --- tarantool.git.orig/test/app/fiber.result
> +++ tarantool.git/test/app/fiber.result
> @@ -1454,6 +1454,17 @@ ch1:put(1)
>  while f:status() ~= 'dead' do fiber.sleep(0.01) end
>  ---
>  ...
> +--
> +-- Test if fiber join() does not crash
> +-- if unjoinable
> +--
> +fj = require('fiber')
> +---
> +...
> +fj.join(fj.self())
> +---
> +- error: the fiber is not joinable
> +...
>  -- cleanup
>  test_run:cmd("clear filter")
>  ---
> Index: tarantool.git/test/app/fiber.test.lua
> ===================================================================
> --- tarantool.git.orig/test/app/fiber.test.lua
> +++ tarantool.git/test/app/fiber.test.lua
> @@ -623,6 +623,13 @@ ch1:put(1)
> 
>  while f:status() ~= 'dead' do fiber.sleep(0.01) end
> 
> +--
> +-- Test if fiber join() does not crash
> +-- if unjoinable
> +--
> +fj = require('fiber')
> +fj.join(fj.self())
> +
>  -- cleanup
>  test_run:cmd("clear filter")