diff options
| -rw-r--r-- | compat/terminal.c | 132 |
1 files changed, 129 insertions, 3 deletions
diff --git a/compat/terminal.c b/compat/terminal.c index 2ae8a6f13e..7db330c52d 100644 --- a/compat/terminal.c +++ b/compat/terminal.c @@ -1,4 +1,4 @@ -#include "git-compat-util.h" +#include "cache.h" #include "compat/terminal.h" #include "sigchain.h" #include "strbuf.h" @@ -24,6 +24,102 @@ static volatile sig_atomic_t term_fd_needs_closing; static int term_fd = -1; static struct termios old_term; +static const char *background_resume_msg; +static const char *restore_error_msg; +static volatile sig_atomic_t ttou_received; + +/* async safe error function for use by signal handlers. */ +static void write_err(const char *msg) +{ + write_in_full(2, "error: ", strlen("error: ")); + write_in_full(2, msg, strlen(msg)); + write_in_full(2, "\n", 1); +} + +static void print_background_resume_msg(int signo) +{ + int saved_errno = errno; + sigset_t mask; + struct sigaction old_sa; + struct sigaction sa = { .sa_handler = SIG_DFL }; + + ttou_received = 1; + write_err(background_resume_msg); + sigaction(signo, &sa, &old_sa); + raise(signo); + sigemptyset(&mask); + sigaddset(&mask, signo); + sigprocmask(SIG_UNBLOCK, &mask, NULL); + /* Stopped here */ + sigprocmask(SIG_BLOCK, &mask, NULL); + sigaction(signo, &old_sa, NULL); + errno = saved_errno; +} + +static void restore_terminal_on_suspend(int signo) +{ + int saved_errno = errno; + int res; + struct termios t; + sigset_t mask; + struct sigaction old_sa; + struct sigaction sa = { .sa_handler = SIG_DFL }; + int can_restore = 1; + + if (tcgetattr(term_fd, &t) < 0) + can_restore = 0; + + if (tcsetattr(term_fd, TCSAFLUSH, &old_term) < 0) + write_err(restore_error_msg); + + sigaction(signo, &sa, &old_sa); + raise(signo); + sigemptyset(&mask); + sigaddset(&mask, signo); + sigprocmask(SIG_UNBLOCK, &mask, NULL); + /* Stopped here */ + sigprocmask(SIG_BLOCK, &mask, NULL); + sigaction(signo, &old_sa, NULL); + if (!can_restore) { + write_err(restore_error_msg); + goto out; + } + /* + * If we resume in the background then we receive SIGTTOU when calling + * tcsetattr() below. Set up a handler to print an error message in that + * case. + */ + sigemptyset(&mask); + sigaddset(&mask, SIGTTOU); + sa.sa_mask = old_sa.sa_mask; + sa.sa_handler = print_background_resume_msg; + sa.sa_flags = SA_RESTART; + sigaction(SIGTTOU, &sa, &old_sa); + again: + ttou_received = 0; + sigprocmask(SIG_UNBLOCK, &mask, NULL); + res = tcsetattr(term_fd, TCSAFLUSH, &t); + sigprocmask(SIG_BLOCK, &mask, NULL); + if (ttou_received) + goto again; + else if (res < 0) + write_err(restore_error_msg); + sigaction(SIGTTOU, &old_sa, NULL); + out: + errno = saved_errno; +} + +static void reset_job_signals(void) +{ + if (restore_error_msg) { + signal(SIGTTIN, SIG_DFL); + signal(SIGTTOU, SIG_DFL); + signal(SIGTSTP, SIG_DFL); + restore_error_msg = NULL; + background_resume_msg = NULL; + } +} + static void close_term_fd(void) { if (term_fd_needs_closing) @@ -40,10 +136,13 @@ void restore_term(void) tcsetattr(term_fd, TCSAFLUSH, &old_term); close_term_fd(); sigchain_pop_common(); + reset_job_signals(); } int save_term(enum save_term_flags flags) { + struct sigaction sa; + if (term_fd < 0) term_fd = ((flags & SAVE_TERM_STDIN) ? 0 @@ -56,6 +155,26 @@ int save_term(enum save_term_flags flags) return -1; } sigchain_push_common(restore_term_on_signal); + /* + * If job control is disabled then the shell will have set the + * disposition of SIGTSTP to SIG_IGN. + */ + sigaction(SIGTSTP, NULL, &sa); + if (sa.sa_handler == SIG_IGN) + return 0; + + /* avoid calling gettext() from signal handler */ + background_resume_msg = _("cannot resume in the background, please use 'fg' to resume"); + restore_error_msg = _("cannot restore terminal settings"); + sa.sa_handler = restore_terminal_on_suspend; + sa.sa_flags = SA_RESTART; + sigemptyset(&sa.sa_mask); + sigaddset(&sa.sa_mask, SIGTSTP); + sigaddset(&sa.sa_mask, SIGTTIN); + sigaddset(&sa.sa_mask, SIGTTOU); + sigaction(SIGTSTP, &sa, NULL); + sigaction(SIGTTIN, &sa, NULL); + sigaction(SIGTTOU, &sa, NULL); return 0; } @@ -78,6 +197,7 @@ static int disable_bits(enum save_term_flags flags, tcflag_t bits) return 0; sigchain_pop_common(); + reset_job_signals(); close_term_fd(); return -1; } @@ -102,6 +222,7 @@ static int getchar_with_timeout(int timeout) fd_set readfds; int res; + again: if (timeout >= 0) { tv.tv_sec = timeout / 1000; tv.tv_usec = (timeout % 1000) * 1000; @@ -111,9 +232,14 @@ static int getchar_with_timeout(int timeout) FD_ZERO(&readfds); FD_SET(0, &readfds); res = select(1, &readfds, NULL, NULL, tvp); - if (res <= 0) + if (!res) return EOF; - + if (res < 0) { + if (errno == EINTR) + goto again; + else + return EOF; + } return getchar(); } |