From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 30 Sep 2014 05:17:20 +0000 (-0700)
Subject: Merge branch 'pr/use-default-sigpipe-setting'
X-Git-Tag: v2.2.0-rc0~70
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/131f0315c46c30d5a9e6743354808230cf4908c0?ds=inline;hp=-c

Merge branch 'pr/use-default-sigpipe-setting'

We used to get confused when a process called us with SIGPIPE
ignored; we do want to die with SIGPIPE when the output is not
read by default, and do ignore the signal when appropriate.

* pr/use-default-sigpipe-setting:
mingw.h: add dummy functions for sigset_t operations
unblock and unignore SIGPIPE
---

131f0315c46c30d5a9e6743354808230cf4908c0
diff --combined git.c
index 4076b014ab,bf4d41f0e6..4cebf32126
--- a/git.c
+++ b/git.c
@@@ -14,13 -14,13 +14,13 @@@ const char git_usage_string[] 
  	"           <command> [<args>]";
  
  const char git_more_info_string[] =
 -	N_("'git help -a' and 'git help -g' lists available subcommands and some\n"
 +	N_("'git help -a' and 'git help -g' list available subcommands and some\n"
  	   "concept guides. See 'git help <command>' or 'git help <concept>'\n"
  	   "to read about a specific subcommand or concept.");
  
  static struct startup_info git_startup_info;
  static int use_pager = -1;
 -static char orig_cwd[PATH_MAX];
 +static char *orig_cwd;
  static const char *env_names[] = {
  	GIT_DIR_ENVIRONMENT,
  	GIT_WORK_TREE_ENVIRONMENT,
@@@ -36,7 -36,8 +36,7 @@@ static void save_env(void
  	if (saved_environment)
  		return;
  	saved_environment = 1;
 -	if (!getcwd(orig_cwd, sizeof(orig_cwd)))
 -		die_errno("cannot getcwd");
 +	orig_cwd = xgetcwd();
  	for (i = 0; i < ARRAY_SIZE(env_names); i++) {
  		orig_env[i] = getenv(env_names[i]);
  		if (orig_env[i])
@@@ -47,9 -48,8 +47,9 @@@
  static void restore_env(void)
  {
  	int i;
 -	if (*orig_cwd && chdir(orig_cwd))
 +	if (orig_cwd && chdir(orig_cwd))
  		die_errno("could not move to %s", orig_cwd);
 +	free(orig_cwd);
  	for (i = 0; i < ARRAY_SIZE(env_names); i++) {
  		if (orig_env[i])
  			setenv(env_names[i], orig_env[i], 1);
@@@ -161,10 -161,9 +161,10 @@@ static int handle_options(const char **
  			if (envchanged)
  				*envchanged = 1;
  		} else if (!strcmp(cmd, "--bare")) {
 -			static char git_dir[PATH_MAX+1];
 +			char *cwd = xgetcwd();
  			is_bare_repository_cfg = 1;
 -			setenv(GIT_DIR_ENVIRONMENT, getcwd(git_dir, sizeof(git_dir)), 0);
 +			setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 +			free(cwd);
  			setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
  			if (envchanged)
  				*envchanged = 1;
@@@ -282,7 -281,8 +282,7 @@@ static int handle_alias(int *argcp, con
  				  "trace: alias expansion: %s =>",
  				  alias_command);
  
 -		new_argv = xrealloc(new_argv, sizeof(char *) *
 -				    (count + *argcp));
 +		REALLOC_ARRAY(new_argv, count + *argcp);
  		/* insert after command name */
  		memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
  
@@@ -592,6 -592,26 +592,26 @@@ static int run_argv(int *argcp, const c
  	return done_alias;
  }
  
+ /*
+  * Many parts of Git have subprograms communicate via pipe, expect the
+  * upstream of a pipe to die with SIGPIPE when the downstream of a
+  * pipe does not need to read all that is written.  Some third-party
+  * programs that ignore or block SIGPIPE for their own reason forget
+  * to restore SIGPIPE handling to the default before spawning Git and
+  * break this carefully orchestrated machinery.
+  *
+  * Restore the way SIGPIPE is handled to default, which is what we
+  * expect.
+  */
+ static void restore_sigpipe_to_default(void)
+ {
+ 	sigset_t unblock;
+ 
+ 	sigemptyset(&unblock);
+ 	sigaddset(&unblock, SIGPIPE);
+ 	sigprocmask(SIG_UNBLOCK, &unblock, NULL);
+ 	signal(SIGPIPE, SIG_DFL);
+ }
  
  int main(int argc, char **av)
  {
@@@ -611,6 -631,8 +631,8 @@@
  	 */
  	sanitize_stdfds();
  
+ 	restore_sigpipe_to_default();
+ 
  	git_setup_gettext();
  
  	trace_command_performance(argv);