+ if (close(fd))
+ child_die(CHILD_ERR_CLOSE);
+}
+
+static void child_close_pair(int fd[2])
+{
+ child_close(fd[0]);
+ child_close(fd[1]);
+}
+
+/*
+ * parent will make it look like the child spewed a fatal error and died
+ * this is needed to prevent changes to t0061.
+ */
+static void fake_fatal(const char *err, va_list params)
+{
+ vreportf("fatal: ", err, params);
+}
+
+static void child_error_fn(const char *err, va_list params)
+{
+ const char msg[] = "error() should not be called in child\n";
+ xwrite(2, msg, sizeof(msg) - 1);
+}
+
+static void child_warn_fn(const char *err, va_list params)
+{
+ const char msg[] = "warn() should not be called in child\n";
+ xwrite(2, msg, sizeof(msg) - 1);
+}
+
+static void NORETURN child_die_fn(const char *err, va_list params)
+{
+ const char msg[] = "die() should not be called in child\n";
+ xwrite(2, msg, sizeof(msg) - 1);
+ _exit(2);
+}
+
+/* this runs in the parent process */
+static void child_err_spew(struct child_process *cmd, struct child_err *cerr)
+{
+ static void (*old_errfn)(const char *err, va_list params);
+
+ old_errfn = get_error_routine();
+ set_error_routine(fake_fatal);
+ errno = cerr->syserr;
+
+ switch (cerr->err) {
+ case CHILD_ERR_CHDIR:
+ error_errno("exec '%s': cd to '%s' failed",
+ cmd->argv[0], cmd->dir);
+ break;
+ case CHILD_ERR_DUP2:
+ error_errno("dup2() in child failed");
+ break;
+ case CHILD_ERR_CLOSE:
+ error_errno("close() in child failed");
+ break;
+ case CHILD_ERR_SIGPROCMASK:
+ error_errno("sigprocmask failed restoring signals");
+ break;
+ case CHILD_ERR_ENOENT:
+ error_errno("cannot run %s", cmd->argv[0]);
+ break;
+ case CHILD_ERR_SILENT:
+ break;
+ case CHILD_ERR_ERRNO:
+ error_errno("cannot exec '%s'", cmd->argv[0]);
+ break;
+ }
+ set_error_routine(old_errfn);
+}
+
+static void prepare_cmd(struct argv_array *out, const struct child_process *cmd)
+{
+ if (!cmd->argv[0])
+ die("BUG: command is empty");
+
+ /*
+ * Add SHELL_PATH so in the event exec fails with ENOEXEC we can
+ * attempt to interpret the command with 'sh'.
+ */
+ argv_array_push(out, SHELL_PATH);
+
+ if (cmd->git_cmd) {
+ argv_array_push(out, "git");
+ argv_array_pushv(out, cmd->argv);
+ } else if (cmd->use_shell) {
+ prepare_shell_cmd(out, cmd->argv);
+ } else {
+ argv_array_pushv(out, cmd->argv);
+ }
+