[glib] [gio] minor improvements to g_cancellable_cancel()

[Benjamin Otte <otte src gnome org>]

commit c85ff0c75004736d5c8798e3b47a47e0fc67ac70
Author: Benjamin Otte <otte gnome org>
Date:   Sun Jul 5 21:34:39 2009 +0200

    [gio] minor improvements to g_cancellable_cancel()
    
    - make this function not crash when cancellable is NULL
    - avoid locking when the cancellable has already been cancelled

 gio/gcancellable.c |   24 ++++++++++++------------
 1 files changed, 12 insertions(+), 12 deletions(-)
---
diff --git a/gio/gcancellable.c b/gio/gcancellable.c
index 888032d..8654883 100644
--- a/gio/gcancellable.c
+++ b/gio/gcancellable.c
@@ -514,27 +514,27 @@ g_cancellable_make_pollfd (GCancellable *cancellable, GPollFD *pollfd)
 void
 g_cancellable_cancel (GCancellable *cancellable)
 {
+  static const char ch = 'x';
   gboolean cancel;
   GCancellablePrivate *priv;
 
+  if (cancellable == NULL ||
+      priv->cancelled)
+    return;
+
   priv = cancellable->priv;
   cancel = FALSE;
 
   G_LOCK(cancellable);
-  if (cancellable != NULL &&
-      !priv->cancelled)
-    {
-      char ch = 'x';
-      cancel = TRUE;
-      priv->cancelled = TRUE;
-      priv->cancelled_running = TRUE;
+  cancel = TRUE;
+  priv->cancelled = TRUE;
+  priv->cancelled_running = TRUE;
 #ifdef G_OS_WIN32
-      if (priv->event)
-	SetEvent(priv->event);
+  if (priv->event)
+    SetEvent(priv->event);
 #endif
-      if (priv->cancel_pipe[1] != -1)
-	write (priv->cancel_pipe[1], &ch, 1);
-    }
+  if (priv->cancel_pipe[1] != -1)
+    write (priv->cancel_pipe[1], &ch, 1);
   G_UNLOCK(cancellable);
 
   if (cancel)