Merge branch 'pf/editor-ignore-sigint' into maint

The behaviour visible to the end users was confusing, when they
attempt to kill a process spawned in the editor that was in turn
launched by Git with SIGINT (or SIGQUIT), as Git would catch that
signal and die.  We ignore these signals now.

* pf/editor-ignore-sigint:
  fix compilation with NO_PTHREADS
  launch_editor: propagate signals from editor to git
  run-command: do not warn about child death from terminal
  launch_editor: ignore terminal signals while editor has control
  launch_editor: refactor to use start/finish_command
  run-command: drop silent_exec_failure arg from wait_or_whine

editor.c

 #include "cache.h"
 #include "strbuf.h"
 #include "run-command.h"
+#include "sigchain.h"
 
 #ifndef DEFAULT_EDITOR
 #define DEFAULT_EDITOR "vi"
@@ -37,8 +38,25 @@ int launch_editor(const char *path, struct strbuf *buffer, const char *const *en
 
 	if (strcmp(editor, ":")) {
 		const char *args[] = { editor, path, NULL };
+		struct child_process p;
+		int ret, sig;
 
-		if (run_command_v_opt_cd_env(args, RUN_USING_SHELL, NULL, env))
+		memset(&p, 0, sizeof(p));
+		p.argv = args;
+		p.env = env;
+		p.use_shell = 1;
+		if (start_command(&p) < 0)
+			return error("unable to start editor '%s'", editor);
+
+		sigchain_push(SIGINT, SIG_IGN);
+		sigchain_push(SIGQUIT, SIG_IGN);
+		ret = finish_command(&p);
+		sig = ret + 128;
+		sigchain_pop(SIGINT);
+		sigchain_pop(SIGQUIT);
+		if (sig == SIGINT || sig == SIGQUIT)
+			raise(sig);
+		if (ret)
 			return error("There was a problem with the editor '%s'.",
 					editor);
 	}

run-command.c

@@ -226,7 +226,7 @@ static inline void set_cloexec(int fd)
 		fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
 }
 
-static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
+static int wait_or_whine(pid_t pid, const char *argv0)
 {
 	int status, code = -1;
 	pid_t waiting;
@@ -242,7 +242,8 @@ static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
 		error("waitpid is confused (%s)", argv0);
 	} else if (WIFSIGNALED(status)) {
 		code = WTERMSIG(status);
-		error("%s died of signal %d", argv0, code);
+		if (code != SIGINT && code != SIGQUIT)
+			error("%s died of signal %d", argv0, code);
 		/*
 		 * This return value is chosen so that code & 0xff
 		 * mimics the exit code that a POSIX shell would report for
@@ -432,8 +433,7 @@ int start_command(struct child_process *cmd)
 		 * At this point we know that fork() succeeded, but execvp()
 		 * failed. Errors have been reported to our stderr.
 		 */
-		wait_or_whine(cmd->pid, cmd->argv[0],
-			      cmd->silent_exec_failure);
+		wait_or_whine(cmd->pid, cmd->argv[0]);
 		failed_errno = errno;
 		cmd->pid = -1;
 	}
@@ -538,7 +538,7 @@ int start_command(struct child_process *cmd)
 
 int finish_command(struct child_process *cmd)
 {
-	return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
+	return wait_or_whine(cmd->pid, cmd->argv[0]);
 }
 
 int run_command(struct child_process *cmd)
@@ -725,7 +725,7 @@ int start_async(struct async *async)
 int finish_async(struct async *async)
 {
 #ifdef NO_PTHREADS
-	return wait_or_whine(async->pid, "child process", 0);
+	return wait_or_whine(async->pid, "child process");
 #else
 	void *ret = (void *)(intptr_t)(-1);