feat(server): set $NVIM, unset $NVIM_LISTEN_ADDRESS #11009

PROBLEM
------------------------------------------------------------------------
$NVIM_LISTEN_ADDRESS has conflicting purposes as both a parameter ("the
current process should listen on this address") and a descriptor ("the
current process is a child of this address").

This contradiction means the presence of NVIM_LISTEN_ADDRESS is
ambiguous, so child Nvim always tries to listen on its _parent's_
socket. This is the cause of lots of  "Failed to start server" spam in
our test/CI logs:

    WARN  2022-04-30… server_start:154: Failed to start server: address already in use: \\.\pipe\nvim-4480-0
    WARN  2022-04-30… server_start:154: Failed to start server: address already in use: \\.\pipe\nvim-2168-0

SOLUTION
------------------------------------------------------------------------

1. Set $NVIM to the parent v:servername, *only* in child processes.
   - Now the correct way to detect a "parent" Nvim is to check for $NVIM.
2. Do NOT set $NVIM_LISTEN_ADDRESS in child processes.
3. On startup if $NVIM_LISTEN_ADDRESS exists, unset it immediately after
   server init.
4. Open a channel to parent automatically, expose it as v:parent.

Fixes #3118
Fixes #6764
Fixes #9336
Ref https://github.com/neovim/neovim/pull/8247#issuecomment-380275696
Ref #8696
This commit is contained in:
Justin M. Keyes
2022-05-03 15:08:35 +02:00
committed by GitHub
parent b5c15ba7e5
commit 4fb48c5654
17 changed files with 157 additions and 245 deletions

View File

@@ -5088,6 +5088,16 @@ static dict_T *create_environment(const dictitem_T *job_env, const bool clear_en
tv_dict_add_str(env, S_LEN("TERM"), pty_term_name);
}
// Set $NVIM (in the child process) to v:servername. #3118
char *nvim_addr = (char *)get_vim_var_str(VV_SEND_SERVER);
if (nvim_addr[0] != '\0') {
dictitem_T *dv = tv_dict_find(env, S_LEN("NVIM"));
if (dv) {
tv_dict_item_remove(env, dv);
}
tv_dict_add_str(env, S_LEN("NVIM"), nvim_addr);
}
if (job_env) {
#ifdef WIN32
TV_DICT_ITER(job_env->di_tv.vval.v_dict, var, {