[PATCH] fix swap across multiple screens

exchange_with_frame now always selects the second frame given,
simplifying the code (getting rid of segfaults when both were
on different screens). This changes the behaviour of cmd_swap
to always focus the first argument when two arguments are given.

This patch also removes the screen argument of exchange_with_frame,
which is now no longer needed (and cmd_swap was giving the wrong
screen anyway in the case of multiple arguments given).
---
 src/actions.c |   10 +++++-----
 src/split.c   |   30 ++----------------------------
 src/split.h   |    2 +-
 3 files changed, 8 insertions(+), 34 deletions(-)

 May I push it?

diff --git a/src/actions.c b/src/actions.c
index bda8002..052b099 100644
--- a/src/actions.c
+++ b/src/actions.c
@@ -4292,7 +4292,7 @@ cmd_exchangeup (int interactive UNUSED, struct cmdarg **args UNUSED)
   rp_frame *frame;
 
   if ((frame = find_frame_up (current_frame())))
-    exchange_with_frame (current_screen(), current_frame(), frame);
+    exchange_with_frame (current_frame(), frame);
 
   return cmdret_new (RET_SUCCESS, NULL);
 }
@@ -4303,7 +4303,7 @@ cmd_exchangedown (int interactive UNUSED, struct cmdarg **args UNUSED)
   rp_frame *frame;
 
   if ((frame = find_frame_down (current_frame())))
-    exchange_with_frame (current_screen(), current_frame(), frame);
+    exchange_with_frame (current_frame(), frame);
 
   return cmdret_new (RET_SUCCESS, NULL);
 }
@@ -4314,7 +4314,7 @@ cmd_exchangeleft (int interactive UNUSED, struct cmdarg **args UNUSED)
   rp_frame *frame;
 
   if ((frame = find_frame_left (current_frame())))
-    exchange_with_frame (current_screen(), current_frame(), frame);
+    exchange_with_frame (current_frame(), frame);
 
   return cmdret_new (RET_SUCCESS, NULL);
 }
@@ -4325,7 +4325,7 @@ cmd_exchangeright (int interactive UNUSED, struct cmdarg **args UNUSED)
   rp_frame *frame;
 
   if ((frame = find_frame_right (current_frame())))
-    exchange_with_frame (current_screen(), current_frame(), frame);
+    exchange_with_frame (current_frame(), frame);
 
   return cmdret_new (RET_SUCCESS, NULL);
 }
@@ -4347,7 +4347,7 @@ cmd_swap (int interactive UNUSED, struct cmdarg **args)
     	return cmdret_new (RET_FAILURE, "swap: frames on different screens");
     }
 
-  exchange_with_frame (current_screen(), src_frame, dest_frame);
+  exchange_with_frame (src_frame, dest_frame);
 
   return cmdret_new (RET_SUCCESS, NULL);
 }
diff --git a/src/split.c b/src/split.c
index fa6e08f..480fca1 100644
--- a/src/split.c
+++ b/src/split.c
@@ -874,16 +874,10 @@ set_active_frame (rp_frame *frame, int force_indicator)
 }
 
 void
-exchange_with_frame (rp_screen *s, rp_frame *cur, rp_frame *frame)
+exchange_with_frame (rp_frame *cur, rp_frame *frame)
 {
   rp_window *win,*last_win;
 
-  /* As a frame does not tell which screen it belongs to,
-   * we could only make sure the frames are not on different
-   * screens when xinerama is not available, if both have
-   * windows in it. As this is not enough the caller will
-   * have to check this. As I only plan to implement 
-   * exchange_{left,right,up,down}, this will be a nop...*/
   if (frame == NULL || frame == cur) return;
 
   /* Exchange the windows in the frames */
@@ -904,27 +898,7 @@ exchange_with_frame (rp_screen *s, rp_frame *cur, rp_frame *frame)
   /* Make the switch */
   update_last_access (frame);
 
-  if (s->current_frame == cur->number)
-    {
-      s->current_frame = frame->number;
-      /* mark it as active */
-      show_frame_indicator(0);
-    }
-
-  update_bar (s);
-
-
-  XSync (dpy, False);
-
-  hook_run (&rp_switch_frame_hook);
-
-  /* FIXME: Remaining problems:
-   *  - if one of the window is transient, the windows in the
-   *  background could cause problems.
-   *
-   *  - how to implement correct mouse-warping?
-   *  (is it needed at all?)
-   */
+  set_active_frame(frame, 0);
 }
 
 
diff --git a/src/split.h b/src/split.h
index 8332037..87bb660 100644
--- a/src/split.h
+++ b/src/split.h
@@ -41,7 +41,7 @@ rp_window *current_window (void);
 void init_frame_lists (void);
 void init_frame_list (rp_screen *screen);
 void set_active_frame (rp_frame *frame, int force_indicator);
-void exchange_with_frame (rp_screen *s, rp_frame *cur, rp_frame *frame);
+void exchange_with_frame (rp_frame *cur, rp_frame *frame);
 void blank_frame (rp_frame *frame);
 void show_frame_indicator (int force);
 void hide_frame_indicator (void);