From 0f9c90e0edd27d2db04d48e7bd98bb46d2c4a918 Mon Sep 17 00:00:00 2001 From: Matt Widmann Date: Sat, 25 Nov 2017 13:59:07 -0800 Subject: io: retry fgets on EINTR (#7632) The calls to `fgets` in `src/nvim/if_cscope.c` (and elsewhere) can show communication errors to the user if a signal is delivered during its system calls. For plugins that proxy subprocess output into cscope requests, a `SIGCHLD` might *always* interfere with calls into `fgets`. To see this in a debugger, put a breakpoint on `cs_reading_emsg` and watch signals come in (with lldb, using `process handle --notify true --pass true`). Next, run a subcommand from neovim that calls through cscope when it returns. A tag picker plugin, like vim-picker and fzy, with `cscopetag` and `cscopetagorder=0` set, reproduced this reliably. The breakpoint will hit after a `SIGCHLD` is delivered, and `errno` will be set to 4, `EINTR`. The caller of `fgets` should retry when `NULL` is returned with `errno` set to `EINTR`. --- src/nvim/ex_cmds2.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'src/nvim/ex_cmds2.c') diff --git a/src/nvim/ex_cmds2.c b/src/nvim/ex_cmds2.c index 9b8e463aee..ec4ce63e17 100644 --- a/src/nvim/ex_cmds2.c +++ b/src/nvim/ex_cmds2.c @@ -3199,8 +3199,14 @@ static char_u *get_one_sourceline(struct source_cookie *sp) ga_grow(&ga, 120); buf = (char_u *)ga.ga_data; +retry: + errno = 0; if (fgets((char *)buf + ga.ga_len, ga.ga_maxlen - ga.ga_len, sp->fp) == NULL) { + if (errno == EINTR) { + goto retry; + } + break; } len = ga.ga_len + (int)STRLEN(buf + ga.ga_len); -- cgit