1 files changed, 147 insertions, 5 deletions

diff --git a/run-command.c b/run-command.c
index af0c8a10df..33bc63a1de 100644
--- a/run-command.c
+++ b/run-command.c
@@ -864,19 +864,161 @@ int run_hook_le(const char *const *env, const char *name, ...)
 	return ret;
 }
 
-int capture_command(struct child_process *cmd, struct strbuf *buf, size_t hint)
+struct io_pump {
+	/* initialized by caller */
+	int fd;
+	int type; /* POLLOUT or POLLIN */
+	union {
+		struct {
+			const char *buf;
+			size_t len;
+		} out;
+		struct {
+			struct strbuf *buf;
+			size_t hint;
+		} in;
+	} u;
+
+	/* returned by pump_io */
+	int error; /* 0 for success, otherwise errno */
+
+	/* internal use */
+	struct pollfd *pfd;
+};
+
+static int pump_io_round(struct io_pump *slots, int nr, struct pollfd *pfd)
+{
+	int pollsize = 0;
+	int i;
+
+	for (i = 0; i < nr; i++) {
+		struct io_pump *io = &slots[i];
+		if (io->fd < 0)
+			continue;
+		pfd[pollsize].fd = io->fd;
+		pfd[pollsize].events = io->type;
+		io->pfd = &pfd[pollsize++];
+	}
+
+	if (!pollsize)
+		return 0;
+
+	if (poll(pfd, pollsize, -1) < 0) {
+		if (errno == EINTR)
+			return 1;
+		die_errno("poll failed");
+	}
+
+	for (i = 0; i < nr; i++) {
+		struct io_pump *io = &slots[i];
+
+		if (io->fd < 0)
+			continue;
+
+		if (!(io->pfd->revents & (POLLOUT|POLLIN|POLLHUP|POLLERR|POLLNVAL)))
+			continue;
+
+		if (io->type == POLLOUT) {
+			ssize_t len = xwrite(io->fd,
+					     io->u.out.buf, io->u.out.len);
+			if (len < 0) {
+				io->error = errno;
+				close(io->fd);
+				io->fd = -1;
+			} else {
+				io->u.out.buf += len;
+				io->u.out.len -= len;
+				if (!io->u.out.len) {
+					close(io->fd);
+					io->fd = -1;
+				}
+			}
+		}
+
+		if (io->type == POLLIN) {
+			ssize_t len = strbuf_read_once(io->u.in.buf,
+						       io->fd, io->u.in.hint);
+			if (len < 0)
+				io->error = errno;
+			if (len <= 0) {
+				close(io->fd);
+				io->fd = -1;
+			}
+		}
+	}
+
+	return 1;
+}
+
+static int pump_io(struct io_pump *slots, int nr)
+{
+	struct pollfd *pfd;
+	int i;
+
+	for (i = 0; i < nr; i++)
+		slots[i].error = 0;
+
+	ALLOC_ARRAY(pfd, nr);
+	while (pump_io_round(slots, nr, pfd))
+		; /* nothing */
+	free(pfd);
+
+	/* There may be multiple errno values, so just pick the first. */
+	for (i = 0; i < nr; i++) {
+		if (slots[i].error) {
+			errno = slots[i].error;
+			return -1;
+		}
+	}
+	return 0;
+}
+
+
+int pipe_command(struct child_process *cmd,
+		 const char *in, size_t in_len,
+		 struct strbuf *out, size_t out_hint,
+		 struct strbuf *err, size_t err_hint)
 {
-	cmd->out = -1;
+	struct io_pump io[3];
+	int nr = 0;
+
+	if (in)
+		cmd->in = -1;
+	if (out)
+		cmd->out = -1;
+	if (err)
+		cmd->err = -1;
+
 	if (start_command(cmd) < 0)
 		return -1;
 
-	if (strbuf_read(buf, cmd->out, hint) < 0) {
-		close(cmd->out);
+	if (in) {
+		io[nr].fd = cmd->in;
+		io[nr].type = POLLOUT;
+		io[nr].u.out.buf = in;
+		io[nr].u.out.len = in_len;
+		nr++;
+	}
+	if (out) {
+		io[nr].fd = cmd->out;
+		io[nr].type = POLLIN;
+		io[nr].u.in.buf = out;
+		io[nr].u.in.hint = out_hint;
+		nr++;
+	}
+	if (err) {
+		io[nr].fd = cmd->err;
+		io[nr].type = POLLIN;
+		io[nr].u.in.buf = err;
+		io[nr].u.in.hint = err_hint;
+		nr++;
+	}
+
+	if (pump_io(io, nr) < 0) {
 		finish_command(cmd); /* throw away exit code */
 		return -1;
 	}
 
-	close(cmd->out);
 	return finish_command(cmd);
 }