ynkdir-imactivatekey patch from [ynkdir's google code](http://code.google.com/r/yukihironakadaira-vim/source/browse/?name=ynkdir-imactivatekey)

ynkdir-imactivatekey.patch

diff -r 799a3e43b0b5 src/gui.c
--- a/src/gui.c	Fri Jun 28 11:52:13 2013 +0900
+++ b/src/gui.c	Fri Jun 28 12:01:36 2013 +0900
@@ -771,10 +771,6 @@
 	    gui_mch_disable_beval_area(balloonEval);
 #endif
 
-#if defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
-	if (!im_xim_isvalid_imactivate())
-	    EMSG(_("E599: Value of 'imactivatekey' is invalid"));
-#endif
 	/* When 'cmdheight' was set during startup it may not have taken
 	 * effect yet. */
 	if (p_ch != 1L)
@@ -1131,13 +1127,7 @@
 		static int iid;
 		guicolor_T fg, bg;
 
-		if (
-# if defined(FEAT_GUI_GTK) && !defined(FEAT_HANGULIN)
-			preedit_get_status()
-# else
-			im_get_status()
-# endif
-			)
+		if (im_get_status())
 		{
 		    iid = syn_name2id((char_u *)"CursorIM");
 		    if (iid > 0)
diff -r 799a3e43b0b5 src/mbyte.c
--- a/src/mbyte.c	Fri Jun 28 11:52:13 2013 +0900
+++ b/src/mbyte.c	Fri Jun 28 12:01:36 2013 +0900
@@ -4439,11 +4439,8 @@
 static int xim_has_preediting INIT(= FALSE);  /* IM current status */
 
 static int im_is_active	       = FALSE;	/* IM is enabled for current mode    */
-static int preedit_is_active   = FALSE;
 
 static unsigned long im_commit_handler_id  = 0;
-static unsigned int  im_activatekey_keyval = GDK_VoidSymbol;
-static unsigned int  im_activatekey_state  = 0;
 
 static GtkWidget *preedit_window = NULL;
 static GtkWidget *preedit_label = NULL;
@@ -4694,11 +4691,6 @@
 #ifdef XIM_DEBUG
     xim_log("im_preedit_start_cb()\n");
 #endif
-
-    im_is_active = TRUE;
-    preedit_is_active = TRUE;
-    gui_update_cursor(TRUE, FALSE);
-    im_show_info();
 }
 
 /*
@@ -4714,16 +4706,6 @@
 
     /* Indicate that preediting has finished */
     xim_has_preediting = FALSE;
-
-#if 0
-    /* Removal of this line suggested by Takuhiro Nishioka.  Fixes that IM was
-     * switched off unintentionally.  We now use preedit_is_active (added by
-     * SungHyun Nam). */
-    im_is_active = FALSE;
-#endif
-    preedit_is_active = FALSE;
-    gui_update_cursor(TRUE, FALSE);
-    im_show_info();
 }
 
 /*
@@ -4836,112 +4818,6 @@
     xim_has_preediting = FALSE;
 }
 
-/*
- * Convert the string argument to keyval and state for GdkEventKey.
- * If str is valid return TRUE, otherwise FALSE.
- *
- * See 'imactivatekey' for documentation of the format.
- */
-    static int
-im_string_to_keyval(const char *str, unsigned int *keyval, unsigned int *state)
-{
-    const char	    *mods_end;
-    unsigned	    tmp_keyval;
-    unsigned	    tmp_state = 0;
-
-    mods_end = strrchr(str, '-');
-    mods_end = (mods_end != NULL) ? mods_end + 1 : str;
-
-    /* Parse modifier keys */
-    while (str < mods_end)
-	switch (*str++)
-	{
-	    case '-':							break;
-	    case 'S': case 's': tmp_state |= (unsigned)GDK_SHIFT_MASK;	break;
-	    case 'L': case 'l': tmp_state |= (unsigned)GDK_LOCK_MASK;	break;
-	    case 'C': case 'c': tmp_state |= (unsigned)GDK_CONTROL_MASK;break;
-	    case '1':		tmp_state |= (unsigned)GDK_MOD1_MASK;	break;
-	    case '2':		tmp_state |= (unsigned)GDK_MOD2_MASK;	break;
-	    case '3':		tmp_state |= (unsigned)GDK_MOD3_MASK;	break;
-	    case '4':		tmp_state |= (unsigned)GDK_MOD4_MASK;	break;
-	    case '5':		tmp_state |= (unsigned)GDK_MOD5_MASK;	break;
-	    default:
-		return FALSE;
-	}
-
-    tmp_keyval = gdk_keyval_from_name(str);
-
-    if (tmp_keyval == 0 || tmp_keyval == GDK_VoidSymbol)
-	return FALSE;
-
-    if (keyval != NULL)
-	*keyval = tmp_keyval;
-    if (state != NULL)
-	*state = tmp_state;
-
-    return TRUE;
-}
-
-/*
- * Return TRUE if p_imak is valid, otherwise FALSE.  As a special case, an
- * empty string is also regarded as valid.
- *
- * Note: The numerical key value of p_imak is cached if it was valid; thus
- * boldly assuming im_xim_isvalid_imactivate() will always be called whenever
- * 'imak' changes.  This is currently the case but not obvious -- should
- * probably rename the function for clarity.
- */
-    int
-im_xim_isvalid_imactivate(void)
-{
-    if (p_imak[0] == NUL)
-    {
-	im_activatekey_keyval = GDK_VoidSymbol;
-	im_activatekey_state  = 0;
-	return TRUE;
-    }
-
-    return im_string_to_keyval((const char *)p_imak,
-			       &im_activatekey_keyval,
-			       &im_activatekey_state);
-}
-
-    static void
-im_synthesize_keypress(unsigned int keyval, unsigned int state)
-{
-    GdkEventKey *event;
-
-#  ifdef HAVE_GTK_MULTIHEAD
-    event = (GdkEventKey *)gdk_event_new(GDK_KEY_PRESS);
-    g_object_ref(gui.drawarea->window); /* unreffed by gdk_event_free() */
-#  else
-    event = (GdkEventKey *)g_malloc0((gulong)sizeof(GdkEvent));
-    event->type = GDK_KEY_PRESS;
-#  endif
-    event->window = gui.drawarea->window;
-    event->send_event = TRUE;
-    event->time = GDK_CURRENT_TIME;
-    event->state  = state;
-    event->keyval = keyval;
-    event->hardware_keycode = /* needed for XIM */
-	XKeysymToKeycode(GDK_WINDOW_XDISPLAY(event->window), (KeySym)keyval);
-    event->length = 0;
-    event->string = NULL;
-
-    gtk_im_context_filter_keypress(xic, event);
-
-    /* For consistency, also send the corresponding release event. */
-    event->type = GDK_KEY_RELEASE;
-    event->send_event = FALSE;
-    gtk_im_context_filter_keypress(xic, event);
-
-#  ifdef HAVE_GTK_MULTIHEAD
-    gdk_event_free((GdkEvent *)event);
-#  else
-    g_free(event);
-#  endif
-}
-
     void
 xim_reset(void)
 {
@@ -4965,22 +4841,6 @@
 		    argv[0] = (char_u *)"0";
 		(void)call_func_retnr(p_imaf, 1, argv, FALSE);
 	    }
-	    else if (im_activatekey_keyval != GDK_VoidSymbol)
-	    {
-		if (im_is_active)
-		{
-		    g_signal_handler_block(xic, im_commit_handler_id);
-		    im_synthesize_keypress(im_activatekey_keyval,
-						    im_activatekey_state);
-		    g_signal_handler_unblock(xic, im_commit_handler_id);
-		}
-	    }
-	    else
-	    {
-		im_shutdown();
-		xim_init();
-		xim_set_focus(gui.in_focus);
-	    }
 	}
     }
 
@@ -5032,75 +4892,17 @@
      * gtk_im_context_filter_keypress() in Normal mode.
      * And while doing :sh too.
      */
-    if (xic != NULL && !p_imdisable
-		    && (State & (INSERT | CMDLINE | NORMAL | EXTERNCMD)) != 0)
+    if (xic != NULL && !p_imdisable)
     {
-	/*
-	 * Filter 'imactivatekey' and map it to CTRL-^.  This way, Vim is
-	 * always aware of the current status of IM, and can even emulate
-	 * the activation key for modules that don't support one.
-	 */
-	if (event->keyval == im_activatekey_keyval
-	     && (event->state & im_activatekey_state) == im_activatekey_state)
-	{
-	    unsigned int state_mask;
-
-	    /* Require the state of the 3 most used modifiers to match exactly.
-	     * Otherwise e.g. <S-C-space> would be unusable for other purposes
-	     * if the IM activate key is <S-space>. */
-	    state_mask  = im_activatekey_state;
-	    state_mask |= ((int)GDK_SHIFT_MASK | (int)GDK_CONTROL_MASK
-							| (int)GDK_MOD1_MASK);
-
-	    if ((event->state & state_mask) != im_activatekey_state)
-		return FALSE;
-
-	    /* Don't send it a second time on GDK_KEY_RELEASE. */
-	    if (event->type != GDK_KEY_PRESS)
-		return TRUE;
-
-	    if (map_to_exists_mode((char_u *)"", LANGMAP, FALSE))
-	    {
-		im_set_active(FALSE);
-
-		/* ":lmap" mappings exists, toggle use of mappings. */
-		State ^= LANGMAP;
-		if (State & LANGMAP)
-		{
-		    curbuf->b_p_iminsert = B_IMODE_NONE;
-		    State &= ~LANGMAP;
-		}
-		else
-		{
-		    curbuf->b_p_iminsert = B_IMODE_LMAP;
-		    State |= LANGMAP;
-		}
-		return TRUE;
-	    }
-
-	    return gtk_im_context_filter_keypress(xic, event);
-	}
-
-	/* Don't filter events through the IM context if IM isn't active
-	 * right now.  Unlike with GTK+ 1.2 we cannot rely on the IM module
-	 * not doing anything before the activation key was sent. */
-	if (im_activatekey_keyval == GDK_VoidSymbol || im_is_active)
-	{
-	    int imresult = gtk_im_context_filter_keypress(xic, event);
-
-	    /* If XIM tried to commit a keypad key as a single char.,
-	     * ignore it so we can use the keypad key 'raw', for mappings. */
-	    if (xim_expected_char != NUL && xim_ignored_char)
-		/* We had a keypad key, and XIM tried to thieve it */
-		return FALSE;
-
-	    /* This is supposed to fix a problem with iBus, that space
-	     * characters don't work in input mode. */
-	    xim_expected_char = NUL;
-
-	    /* Normal processing */
-	    return imresult;
-	}
+	int imresult = gtk_im_context_filter_keypress(xic, event);
+
+	/* If XIM tried to commit a keypad key as a single char.,
+	 * ignore it so we can use the keypad key 'raw', for mappings. */
+	if (xim_expected_char != NUL && xim_ignored_char)
+	    /* We had a keypad key, and XIM tried to thieve it */
+	    return FALSE;
+
+	return imresult;
     }
 
     return FALSE;
@@ -5131,12 +4933,6 @@
 }
 
     int
-preedit_get_status(void)
-{
-    return preedit_is_active;
-}
-
-    int
 im_is_preediting()
 {
     return xim_has_preediting;
diff -r 799a3e43b0b5 src/option.c
--- a/src/option.c	Fri Jun 28 11:52:13 2013 +0900
+++ b/src/option.c	Fri Jun 28 12:01:36 2013 +0900
@@ -1477,13 +1477,6 @@
 			    {(char_u *)NULL, (char_u *)0L}
 # endif
 			    SCRIPTID_INIT},
-    {"imactivatekey","imak",P_STRING|P_VI_DEF,
-#if defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
-			    (char_u *)&p_imak, PV_NONE,
-#else
-			    (char_u *)NULL, PV_NONE,
-#endif
-			    {(char_u *)"", (char_u *)0L} SCRIPTID_INIT},
     {"imcmdline",   "imc",  P_BOOL|P_VI_DEF,
 #ifdef USE_IM_CONTROL
 			    (char_u *)&p_imcmdline, PV_NONE,
@@ -6102,14 +6095,6 @@
     }
 #endif
 
-#if defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
-    else if (varp == &p_imak)
-    {
-	if (gui.in_use && !im_xim_isvalid_imactivate())
-	    errmsg = e_invarg;
-    }
-#endif
-
 #ifdef FEAT_KEYMAP
     else if (varp == &curbuf->b_p_keymap)
     {
diff -r 799a3e43b0b5 src/option.h
--- a/src/option.h	Fri Jun 28 11:52:13 2013 +0900
+++ b/src/option.h	Fri Jun 28 12:01:36 2013 +0900
@@ -561,7 +561,6 @@
 #endif
 EXTERN int	p_ic;		/* 'ignorecase' */
 #if defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
-EXTERN char_u	*p_imak;	/* 'imactivatekey' */
 EXTERN char_u	*p_imaf;	/* 'imactivatefunc' */
 EXTERN char_u	*p_imsf;	/* 'imstatusfunc' */
 #endif
diff -r 799a3e43b0b5 src/proto/mbyte.pro
--- a/src/proto/mbyte.pro	Fri Jun 28 11:52:13 2013 +0900
+++ b/src/proto/mbyte.pro	Fri Jun 28 12:01:36 2013 +0900
@@ -78,11 +78,9 @@
 void xim_set_preedit __ARGS((void));
 void xim_init __ARGS((void));
 void im_shutdown __ARGS((void));
-int im_xim_isvalid_imactivate __ARGS((void));
 void xim_reset __ARGS((void));
 int xim_queue_key_press_event __ARGS((GdkEventKey *event, int down));
 int im_get_status __ARGS((void));
-int preedit_get_status __ARGS((void));
 int im_is_preediting __ARGS((void));
 void xim_set_status_area __ARGS((void));
 int xim_get_status_area_height __ARGS((void));
diff -r 799a3e43b0b5 src/screen.c
--- a/src/screen.c	Fri Jun 28 11:52:13 2013 +0900
+++ b/src/screen.c	Fri Jun 28 12:01:36 2013 +0900
@@ -9531,13 +9531,7 @@
 	{
 	    MSG_PUTS_ATTR("--", attr);
 #if defined(FEAT_XIM)
-	    if (
-# ifdef FEAT_GUI_GTK
-		    preedit_get_status()
-# else
-		    im_get_status()
-# endif
-	       )
+	    if (im_get_status())
 # ifdef FEAT_GUI_GTK /* most of the time, it's not XIM being used */
 		MSG_PUTS_ATTR(" IM", attr);
 # else