patch: include flag-only file changes in "special" when filtering (
issue5864)
This patch fix the
issue5864 (or maybe
issue5865 too) which occurs during
split (or I should say at the time of filtering the hunks in interactive
mode) where user hits a not ending loop of "no changes to record".
And it's not only the case for split it will happen in every interactive
case for e.g. `hg commit -i` or `hg uncommit -i`
After looking into code I found that when filtering we have some
notation called "special" for the file headers which doesn't contain
any hunk and just contain the header (for e.g. newly added empty file
or deleted file) where the user cannot change the content of operation.
And I think we can put this "flag-only" file change in that same bucket
of "special". But I doubt a bit about the case when a file have flag change
and atleast one hunk then user won't be able to separate the flag change
from hunks.
Changed test file reflect the fixed behaviour.
Differential Revision: https://phab.mercurial-scm.org/D6058
/*
* 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;
}
}