[gnome-terminal] screen: Fix check for foreground process

[Christian Persch <chpe src gnome org>]

commit af1205c42cfaac4e6249d893a3aad9e4aaafe7cc
Author: Christian Persch <chpe gnome org>
Date:   Mon Feb 13 20:00:41 2017 +0100

    screen: Fix check for foreground process
    
    While the async spawning is in progress but not complete (or failed) yet,
    the has-foreground-process check would falsely return TRUE.

 src/terminal-screen.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/terminal-screen.c b/src/terminal-screen.c
index 06f5db2..63f0ca2 100644
--- a/src/terminal-screen.c
+++ b/src/terminal-screen.c
@@ -2055,6 +2055,9 @@ terminal_screen_has_foreground_process (TerminalScreen *screen,
   gsize len;
   int fgpid;
 
+  if (priv->child_pid == -1)
+    return FALSE;
+
   pty = vte_terminal_get_pty (VTE_TERMINAL (screen));
   if (pty == NULL)
     return FALSE;