common-main: call restore_sigpipe_to_default()
[git/git.git] / common-main.c
1 #include "cache.h"
2 #include "exec_cmd.h"
3
4 /*
5 * Many parts of Git have subprograms communicate via pipe, expect the
6 * upstream of a pipe to die with SIGPIPE when the downstream of a
7 * pipe does not need to read all that is written. Some third-party
8 * programs that ignore or block SIGPIPE for their own reason forget
9 * to restore SIGPIPE handling to the default before spawning Git and
10 * break this carefully orchestrated machinery.
11 *
12 * Restore the way SIGPIPE is handled to default, which is what we
13 * expect.
14 */
15 static void restore_sigpipe_to_default(void)
16 {
17 sigset_t unblock;
18
19 sigemptyset(&unblock);
20 sigaddset(&unblock, SIGPIPE);
21 sigprocmask(SIG_UNBLOCK, &unblock, NULL);
22 signal(SIGPIPE, SIG_DFL);
23 }
24
25 int main(int argc, char **av)
26 {
27 /*
28 * This const trickery is explained in
29 * 84d32bf7678259c08406571cd6ce4b7a6724dcba
30 */
31 const char **argv = (const char **)av;
32
33 /*
34 * Always open file descriptors 0/1/2 to avoid clobbering files
35 * in die(). It also avoids messing up when the pipes are dup'ed
36 * onto stdin/stdout/stderr in the child processes we spawn.
37 */
38 sanitize_stdfds();
39
40 argv[0] = git_extract_argv0_path(argv[0]);
41
42 restore_sigpipe_to_default();
43
44 return cmd_main(argc, argv);
45 }