patch 7.4.961
Problem:    Test107 fails in some circunstances.
Solution:   When using "zt", "zb" and "z=" recompute the fraction.
diff --git a/src/proto/window.pro b/src/proto/window.pro
index 0d719f0..ffead2c 100644
--- a/src/proto/window.pro
+++ b/src/proto/window.pro
@@ -53,6 +53,7 @@
 void win_setminheight __ARGS((void));
 void win_drag_status_line __ARGS((win_T *dragwin, int offset));
 void win_drag_vsep_line __ARGS((win_T *dragwin, int offset));
+void set_fraction __ARGS((win_T *wp));
 void win_new_height __ARGS((win_T *wp, int height));
 void win_new_width __ARGS((win_T *wp, int width));
 void win_comp_scroll __ARGS((win_T *wp));