patch 9.0.0490: using freed memory with cmdwin and BufEnter autocmd

Problem:    Using freed memory with cmdwin and BufEnter autocmd.
Solution:   Make sure pointer to b_p_iminsert is still valid.

src/ex_getln.c

@@ -1587,6 +1587,7 @@ getcmdline_int(
 #endif
     expand_T	xpc;
     long	*b_im_ptr = NULL;
+    buf_T	*b_im_ptr_buf = NULL;	// buffer where b_im_ptr is valid
     cmdline_info_T save_ccline;
     int		did_save_ccline = FALSE;
     int		cmdline_type;
@@ -1683,6 +1684,7 @@ getcmdline_int(
 	    b_im_ptr = &curbuf->b_p_iminsert;
 	else
 	    b_im_ptr = &curbuf->b_p_imsearch;
+	b_im_ptr_buf = curbuf;
 	if (*b_im_ptr == B_IMODE_LMAP)
 	    State |= MODE_LANGMAP;
 #ifdef HAVE_INPUT_METHOD
@@ -2034,7 +2036,8 @@ getcmdline_int(
 		goto cmdline_not_changed;
 
 	case Ctrl_HAT:
-		cmdline_toggle_langmap(b_im_ptr);
+		cmdline_toggle_langmap(
+				    buf_valid(b_im_ptr_buf) ? b_im_ptr : NULL);
 		goto cmdline_not_changed;
 
 //	case '@':   only in very old vi
@@ -2544,7 +2547,8 @@ getcmdline_int(
 #endif
 
 #ifdef HAVE_INPUT_METHOD
-    if (b_im_ptr != NULL && *b_im_ptr != B_IMODE_LMAP)
+    if (b_im_ptr != NULL && buf_valid(b_im_ptr_buf)
+						  && *b_im_ptr != B_IMODE_LMAP)
 	im_save_status(b_im_ptr);
     im_set_active(FALSE);
 #endif

src/testdir/test_cmdwin.vim

@@ -378,5 +378,15 @@ func Test_normal_escape()
   call assert_equal('" bar', @:)
 endfunc
 
+" This was using a pointer to a freed buffer
+func Test_cmdwin_freed_buffer_ptr()
+  au BufEnter * next 0| file 
+  edit 0
+  silent! norm q/
+
+  au! BufEnter
+  bwipe!
+endfunc
+
 
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -703,6 +703,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    490,
 /**/
     489,
 /**/