[glib] thread creation: Simplify error handling

[Ryan Lortie <ryanl src gnome org>]

commit 2f5486f02040b0d5cfc67eb97bd037a0ffd86635
Author: Ryan Lortie <desrt desrt ca>
Date:   Wed Oct 12 22:35:35 2011 -0400

    thread creation: Simplify error handling
    
    Instead of always returning non-NULL and finding out about errors via
    the GError*, return NULL from the backend in the event of an error.

 glib/gthread-posix.c |    5 +++--
 glib/gthread-win32.c |    3 ++-
 glib/gthread.c       |   23 +++++++++--------------
 3 files changed, 14 insertions(+), 17 deletions(-)
---
diff --git a/glib/gthread-posix.c b/glib/gthread-posix.c
index f640c00..4d971e8 100644
--- a/glib/gthread-posix.c
+++ b/glib/gthread-posix.c
@@ -1111,8 +1111,9 @@ g_system_thread_new (GThreadFunc   thread_func,
   if (ret == EAGAIN)
     {
       g_set_error (error, G_THREAD_ERROR, G_THREAD_ERROR_AGAIN, 
-		   "Error creating thread: %s", g_strerror (ret));
-      return thread;
+                   "Error creating thread: %s", g_strerror (ret));
+      g_slice_free (GRealThread, thread);
+      return NULL;
     }
 
   posix_check_err (ret, "pthread_create");
diff --git a/glib/gthread-win32.c b/glib/gthread-win32.c
index e380b84..2babc92 100644
--- a/glib/gthread-win32.c
+++ b/glib/gthread-win32.c
@@ -518,7 +518,8 @@ g_system_thread_new (GThreadFunc   func,
                    "Error creating thread: %s", win_error);
       g_free (retval);
       g_free (win_error);
-      return thread;
+      g_slice_free (GRealThread, thread);
+      return NULL;
     }
 
   *(GThreadData **) &(thread->system_thread) = retval;
diff --git a/glib/gthread.c b/glib/gthread.c
index e259bad..7896df8 100644
--- a/glib/gthread.c
+++ b/glib/gthread.c
@@ -799,27 +799,22 @@ g_thread_new_internal (const gchar   *name,
                        gsize          stack_size,
                        GError       **error)
 {
-  GRealThread *result;
-  GError *local_error = NULL;
+  GRealThread *thread;
 
   g_return_val_if_fail (func != NULL, NULL);
 
   G_LOCK (g_thread_new);
-  result = g_system_thread_new (proxy, stack_size, joinable, &local_error);
-  result->thread.joinable = joinable;
-  result->thread.func = func;
-  result->thread.data = data;
-  result->name = name;
-  G_UNLOCK (g_thread_new);
-
-  if (local_error)
+  thread = g_system_thread_new (proxy, stack_size, joinable, error);
+  if (thread)
     {
-      g_propagate_error (error, local_error);
-      g_system_thread_free (result);
-      return NULL;
+      thread->thread.joinable = joinable;
+      thread->thread.func = func;
+      thread->thread.data = data;
+      thread->name = name;
     }
+  G_UNLOCK (g_thread_new);
 
-  return (GThread*) result;
+  return (GThread*) thread;
 }
 
 /**