imap-send: use separate read and write fds

This is a patch that enables us to use the run-command
API, which is supported on Windows.

Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

imap-send.c

@@ -151,7 +151,7 @@ struct imap_list {
 };
 
 struct imap_socket {
-	int fd;
+	int fd[2];
 	SSL *ssl;
 };
 
@@ -301,8 +301,12 @@ static int ssl_socket_connect(struct imap_socket *sock, int use_tls_only, int ve
 		ssl_socket_perror("SSL_new");
 		return -1;
 	}
-	if (!SSL_set_fd(sock->ssl, sock->fd)) {
-		ssl_socket_perror("SSL_set_fd");
+	if (!SSL_set_rfd(sock->ssl, sock->fd[0])) {
+		ssl_socket_perror("SSL_set_rfd");
+		return -1;
+	}
+	if (!SSL_set_wfd(sock->ssl, sock->fd[1])) {
+		ssl_socket_perror("SSL_set_wfd");
 		return -1;
 	}
 
@@ -324,11 +328,12 @@ static int socket_read(struct imap_socket *sock, char *buf, int len)
 		n = SSL_read(sock->ssl, buf, len);
 	else
 #endif
-		n = xread(sock->fd, buf, len);
+		n = xread(sock->fd[0], buf, len);
 	if (n <= 0) {
 		socket_perror("read", sock, n);
-		close(sock->fd);
-		sock->fd = -1;
+		close(sock->fd[0]);
+		close(sock->fd[1]);
+		sock->fd[0] = sock->fd[1] = -1;
 	}
 	return n;
 }
@@ -341,11 +346,12 @@ static int socket_write(struct imap_socket *sock, const char *buf, int len)
 		n = SSL_write(sock->ssl, buf, len);
 	else
 #endif
-		n = write_in_full(sock->fd, buf, len);
+		n = write_in_full(sock->fd[1], buf, len);
 	if (n != len) {
 		socket_perror("write", sock, n);
-		close(sock->fd);
-		sock->fd = -1;
+		close(sock->fd[0]);
+		close(sock->fd[1]);
+		sock->fd[0] = sock->fd[1] = -1;
 	}
 	return n;
 }
@@ -358,7 +364,8 @@ static void socket_shutdown(struct imap_socket *sock)
 		SSL_free(sock->ssl);
 	}
 #endif
-	close(sock->fd);
+	close(sock->fd[0]);
+	close(sock->fd[1]);
 }
 
 /* simple line buffering */
@@ -911,7 +918,7 @@ static void imap_close_server(struct imap_store *ictx)
 {
 	struct imap *imap = ictx->imap;
 
-	if (imap->buf.sock.fd != -1) {
+	if (imap->buf.sock.fd[0] != -1) {
 		imap_exec(ictx, NULL, "LOGOUT");
 		socket_shutdown(&imap->buf.sock);
 	}
@@ -939,7 +946,7 @@ static struct store *imap_open_store(struct imap_server_conf *srvc)
 	ctx = xcalloc(sizeof(*ctx), 1);
 
 	ctx->imap = imap = xcalloc(sizeof(*imap), 1);
-	imap->buf.sock.fd = -1;
+	imap->buf.sock.fd[0] = imap->buf.sock.fd[1] = -1;
 	imap->in_progress_append = &imap->in_progress;
 
 	/* open connection to IMAP server */
@@ -966,7 +973,8 @@ static struct store *imap_open_store(struct imap_server_conf *srvc)
 
 		close(a[0]);
 
-		imap->buf.sock.fd = a[1];
+		imap->buf.sock.fd[0] = a[1];
+		imap->buf.sock.fd[1] = dup(a[1]);
 
 		imap_info("ok\n");
 	} else {
@@ -1043,7 +1051,8 @@ static struct store *imap_open_store(struct imap_server_conf *srvc)
 			goto bail;
 		}
 
-		imap->buf.sock.fd = s;
+		imap->buf.sock.fd[0] = s;
+		imap->buf.sock.fd[1] = dup(s);
 
 		if (srvc->use_ssl &&
 		    ssl_socket_connect(&imap->buf.sock, 0, srvc->ssl_verify)) {