convert: don't drop commits that are empty in the source when using --filemap
I ran into this when using `hg lfconvert --to-normal` (which uses the filemap
class internally), and saw that commits with nothing but a branch change were
dropped. We could put in an option that only lfconvert uses internally. But
silently dropping anything other than a commit where all changes were excluded
seems unintended. For example, there's a message in mercurial_sink.putcommit()
if it drops an empty commit. (And the reason that isn't kicking in here is
because lfconvert isn't passing --filemap, so the self.filemapmode conditional
there is always False.)
The naive change of `return not files` broke test-convert-filemap.t, so this is
a little more elaborate than needed for converting from largefiles.
/*
* Utilities about process handling - signal and subprocess (ex. pager)
*
* Copyright (c) 2011 Yuya Nishihara <yuya@tcha.org>
*
* This software may be used and distributed according to the terms of the
* GNU General Public License version 2 or any later version.
*/
#include <assert.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <sys/wait.h>
#include <unistd.h>
#include "procutil.h"
#include "util.h"
static pid_t pagerpid = 0;
static pid_t peerpgid = 0;
static pid_t peerpid = 0;
static void forwardsignal(int sig)
{
assert(peerpid > 0);
if (kill(peerpid, sig) < 0)
abortmsgerrno("cannot kill %d", peerpid);
debugmsg("forward signal %d", sig);
}
static void forwardsignaltogroup(int sig)
{
/* prefer kill(-pgid, sig), fallback to pid if pgid is invalid */
pid_t killpid = peerpgid > 1 ? -peerpgid : peerpid;
if (kill(killpid, sig) < 0)
abortmsgerrno("cannot kill %d", killpid);
debugmsg("forward signal %d to %d", sig, killpid);
}
static void handlestopsignal(int sig)
{
sigset_t unblockset, oldset;
struct sigaction sa, oldsa;
if (sigemptyset(&unblockset) < 0)
goto error;
if (sigaddset(&unblockset, sig) < 0)
goto error;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = SIG_DFL;
sa.sa_flags = SA_RESTART;
if (sigemptyset(&sa.sa_mask) < 0)
goto error;
forwardsignal(sig);
if (raise(sig) < 0) /* resend to self */
goto error;
if (sigaction(sig, &sa, &oldsa) < 0)
goto error;
if (sigprocmask(SIG_UNBLOCK, &unblockset, &oldset) < 0)
goto error;
/* resent signal will be handled before sigprocmask() returns */
if (sigprocmask(SIG_SETMASK, &oldset, NULL) < 0)
goto error;
if (sigaction(sig, &oldsa, NULL) < 0)
goto error;
return;
error:
abortmsgerrno("failed to handle stop signal");
}
static void handlechildsignal(int sig UNUSED_)
{
if (peerpid == 0 || pagerpid == 0)
return;
/* if pager exits, notify the server with SIGPIPE immediately.
* otherwise the server won't get SIGPIPE if it does not write
* anything. (issue5278) */
if (waitpid(pagerpid, NULL, WNOHANG) == pagerpid)
kill(peerpid, SIGPIPE);
}
void setupsignalhandler(pid_t pid, pid_t pgid)
{
if (pid <= 0)
return;
peerpid = pid;
peerpgid = (pgid <= 1 ? 0 : pgid);
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
/* deadly signals meant to be sent to a process group:
* - SIGHUP: usually generated by the kernel, when termination of a
* process causes that process group to become orphaned
* - SIGINT: usually generated by the terminal */
sa.sa_handler = forwardsignaltogroup;
sa.sa_flags = SA_RESTART;
if (sigemptyset(&sa.sa_mask) < 0)
goto error;
if (sigaction(SIGHUP, &sa, NULL) < 0)
goto error;
if (sigaction(SIGINT, &sa, NULL) < 0)
goto error;
/* terminate frontend by double SIGTERM in case of server freeze */
sa.sa_handler = forwardsignal;
sa.sa_flags |= SA_RESETHAND;
if (sigaction(SIGTERM, &sa, NULL) < 0)
goto error;
/* notify the worker about window resize events */
sa.sa_flags = SA_RESTART;
if (sigaction(SIGWINCH, &sa, NULL) < 0)
goto error;
/* forward user-defined signals */
if (sigaction(SIGUSR1, &sa, NULL) < 0)
goto error;
if (sigaction(SIGUSR2, &sa, NULL) < 0)
goto error;
/* propagate job control requests to worker */
sa.sa_handler = forwardsignal;
sa.sa_flags = SA_RESTART;
if (sigaction(SIGCONT, &sa, NULL) < 0)
goto error;
sa.sa_handler = handlestopsignal;
sa.sa_flags = SA_RESTART;
if (sigaction(SIGTSTP, &sa, NULL) < 0)
goto error;
/* get notified when pager exits */
sa.sa_handler = handlechildsignal;
sa.sa_flags = SA_RESTART;
if (sigaction(SIGCHLD, &sa, NULL) < 0)
goto error;
return;
error:
abortmsgerrno("failed to set up signal handlers");
}
void restoresignalhandler(void)
{
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = SIG_DFL;
sa.sa_flags = SA_RESTART;
if (sigemptyset(&sa.sa_mask) < 0)
goto error;
if (sigaction(SIGHUP, &sa, NULL) < 0)
goto error;
if (sigaction(SIGTERM, &sa, NULL) < 0)
goto error;
if (sigaction(SIGWINCH, &sa, NULL) < 0)
goto error;
if (sigaction(SIGCONT, &sa, NULL) < 0)
goto error;
if (sigaction(SIGTSTP, &sa, NULL) < 0)
goto error;
if (sigaction(SIGCHLD, &sa, NULL) < 0)
goto error;
/* ignore Ctrl+C while shutting down to make pager exits cleanly */
sa.sa_handler = SIG_IGN;
if (sigaction(SIGINT, &sa, NULL) < 0)
goto error;
peerpid = 0;
return;
error:
abortmsgerrno("failed to restore signal handlers");
}
/* This implementation is based on hgext/pager.py (post 369741ef7253)
* Return 0 if pager is not started, or pid of the pager */
pid_t setuppager(const char *pagercmd, const char *envp[])
{
assert(pagerpid == 0);
if (!pagercmd)
return 0;
int pipefds[2];
if (pipe(pipefds) < 0)
return 0;
pid_t pid = fork();
if (pid < 0)
goto error;
if (pid > 0) {
close(pipefds[0]);
if (dup2(pipefds[1], fileno(stdout)) < 0)
goto error;
if (isatty(fileno(stderr))) {
if (dup2(pipefds[1], fileno(stderr)) < 0)
goto error;
}
close(pipefds[1]);
pagerpid = pid;
return pid;
} else {
dup2(pipefds[0], fileno(stdin));
close(pipefds[0]);
close(pipefds[1]);
int r =
execle("/bin/sh", "/bin/sh", "-c", pagercmd, NULL, envp);
if (r < 0) {
abortmsgerrno("cannot start pager '%s'", pagercmd);
}
return 0;
}
error:
close(pipefds[0]);
close(pipefds[1]);
abortmsgerrno("failed to prepare pager");
return 0;
}
void waitpager(void)
{
if (pagerpid == 0)
return;
/* close output streams to notify the pager its input ends */
fclose(stdout);
fclose(stderr);
while (1) {
pid_t ret = waitpid(pagerpid, NULL, 0);
if (ret == -1 && errno == EINTR)
continue;
break;
}
}