[vte] Preserve errno for the _vte_pty_* compat API

[Christian Persch <chpe src gnome org>]

commit da94ec83debfbf19e36fec9aea15f619803cee70
Author: Christian Persch <chpe gnome org>
Date:   Wed Mar 24 15:21:49 2010 +0100

    Preserve errno for the _vte_pty_* compat API

 src/pty.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/pty.c b/src/pty.c
index 83a6ec6..0a94ec0 100644
--- a/src/pty.c
+++ b/src/pty.c
@@ -906,9 +906,11 @@ _vte_pty_open_unix98(VtePty *pty,
         if ((buf = _vte_pty_ptsname(fd, error)) == NULL ||
             !_vte_pty_grantpt(fd, error) ||
             !_vte_pty_unlockpt(fd, error)) {
+                int errsv = errno;
                 _vte_debug_print(VTE_DEBUG_PTY,
                                 "PTY setup failed, bailing.\n");
                 close(fd);
+                errno = errsv;
                 return FALSE;
         }