fix(lua): don't crash when lua_tolstring returns NULL for error value

This commit is contained in:
bfredl 2024-03-22 09:36:19 +01:00
parent dc110cba3c
commit 1ca73eae17
2 changed files with 57 additions and 17 deletions

View File

@ -123,6 +123,34 @@ lua_State *get_global_lstate(void)
return global_lstate;
}
/// get error on top of stack as a string
///
/// Might alter the top value on stack in place (but doesn't change stack height)
///
/// "error" points to memory on the lua stack, use
/// or duplicate the string before using "lstate" again
///
/// @param[out] len length of error (can be NULL)
static const char *nlua_get_error(lua_State *lstate, size_t *len)
{
if (luaL_getmetafield(lstate, -1, "__tostring")) {
if (lua_isfunction(lstate, -1) && luaL_callmeta(lstate, -2, "__tostring")) {
// call __tostring, convert the result replace error with it
lua_replace(lstate, -3);
}
// pop __tostring.
lua_pop(lstate, 1);
}
const char *str = lua_tolstring(lstate, -1, len);
if (str == NULL) {
str = "[?????]";
*len = 7;
}
return str;
}
/// Convert lua error into a Vim error message
///
/// @param lstate Lua interpreter state.
@ -131,22 +159,7 @@ void nlua_error(lua_State *const lstate, const char *const msg)
FUNC_ATTR_NONNULL_ALL
{
size_t len;
const char *str = NULL;
if (luaL_getmetafield(lstate, -1, "__tostring")) {
if (lua_isfunction(lstate, -1) && luaL_callmeta(lstate, -2, "__tostring")) {
// call __tostring, convert the result and pop result.
str = lua_tolstring(lstate, -1, &len);
lua_pop(lstate, 1);
}
// pop __tostring.
lua_pop(lstate, 1);
}
if (!str) {
// defer to lua default conversion, this will render tables as [NULL].
str = lua_tolstring(lstate, -1, &len);
}
const char *str = nlua_get_error(lstate, &len);
if (in_script) {
fprintf(stderr, msg, (int)len, str);
@ -216,7 +229,9 @@ static int nlua_luv_cfpcall(lua_State *lstate, int nargs, int nresult, int flags
// consider out of memory errors unrecoverable, just like xmalloc()
preserve_exit(e_outofmem);
}
const char *error = lua_tostring(lstate, -1);
size_t len;
const char *error = nlua_get_error(lstate, &len);
multiqueue_put(main_loop.events, nlua_luv_error_event,
xstrdup(error), (void *)(intptr_t)kCallback);

View File

@ -136,4 +136,29 @@ describe('vim.uv', function()
it("is equal to require('luv')", function()
eq(true, exec_lua("return vim.uv == require('luv')"))
end)
it("doesn't crash on async callbacks throwing nil error", function()
local screen = Screen.new(50, 4)
screen:attach()
screen:set_default_attr_ids {
[1] = { bold = true, reverse = true },
[2] = { background = Screen.colors.Red, foreground = Screen.colors.Grey100 },
[3] = { foreground = Screen.colors.SeaGreen4, bold = true },
}
exec_lua [[
local idle = vim.uv.new_idle()
idle:start(function()
idle:stop()
error()
end)
]]
screen:expect([[
{1: }|
{2:Error executing luv callback:} |
{2:[?????]} |
{3:Press ENTER or type command to continue}^ |
]])
end)
end)