Backport fix for Bug#2423 from trunk.

* dispextern.h (TRY_WINDOW_CHECK_MARGINS)
(TRY_WINDOW_IGNORE_FONTS_CHANGE): New defines.

* xdisp.c (try_window): Change arg from CHECK_MARGINS to FLAGS.
Don't abort with fonts change if TRY_WINDOW_IGNORE_FONTS_CHANGE is
set in FLAGS.  Callers with non-zero CHECK_MARGINS changed to use
TRY_WINDOW_CHECK_MARGINS.

* xfns.c (Fx_show_tip): Undo last change.  Call try_window with
TRY_WINDOW_IGNORE_FONTS_CHANGE (Bug#2423).

diff --cc src/ChangeLog
index a16e35df108ce2400620ebe73a23654e86b7b5a1,2df31f6e57f396612fdedb7daf5846a4604a3afb..1e084a4bc3a4e60b6201911da656bdeddb649b6c
--- 1/src/ChangeLog
--- 2/src/ChangeLog
+++ b/src/ChangeLog
@@@ -1,3 -1,21 +1,16 @@@
 -2010-04-10  YAMAMOTO Mitsuharu  <mituharu@math.s.chiba-u.ac.jp>
++2010-11-04  YAMAMOTO Mitsuharu  <mituharu@math.s.chiba-u.ac.jp>
+ 
+       * dispextern.h (TRY_WINDOW_CHECK_MARGINS)
+       (TRY_WINDOW_IGNORE_FONTS_CHANGE): New defines.
+ 
+       * xdisp.c (try_window): Change arg from CHECK_MARGINS to FLAGS.
+       Don't abort with fonts change if TRY_WINDOW_IGNORE_FONTS_CHANGE is
+       set in FLAGS.  Callers with non-zero CHECK_MARGINS changed to use
+       TRY_WINDOW_CHECK_MARGINS.
+ 
+       * xfns.c (Fx_show_tip): Undo last change.  Call try_window with
+       TRY_WINDOW_IGNORE_FONTS_CHANGE (Bug#2423).
+ 
 -2010-04-09  Jan Djärv  <jan.h.d@swipnet.se>
 -
 -      * xfns.c (Fx_show_tip): Call try_window in a loop until
 -      fonts_changed_p is zero (Bug#2423).
 -
  2010-11-04  Jan Djärv  <jan.h.d@swipnet.se>
  
        * xfns.c (x_real_positions): Only use _NET_FRAME_EXTENTS if our