patch 8.0.0732: when updating a buffer modeless selection is lost commit https://github.com/vim/vim/commit/80dd3f9d41ce2ff6ab3544cdb266627bbdfc34a6 Author: Bram Moolenaar <Bram@vim.org> Date: Wed Jul 19 12:51:52 2017 +0200 patch 8.0.0732: when updating a buffer modeless selection is lost Problem: When updating a buffer for a callback the modeless selection is lost. Solution: Do not insert or delete screen lines when redrawing for a callback and there is a modeless selection.

char*M,A,Z,E=40,J[80],T[3];main(C){for(M=J+E,*J=A=scanf("%d",&
C)            ;--            E;J             [E            ]=M
[E   ]=  E)   printf("._");  for(;(A-=Z=!Z)  ||  (printf("\n|"
)    ,   A    =              39              ,C             --
)    ;   Z    ||    printf   (T   ))T[Z]=Z[A-(E   =A[J-Z])&&!C
&    A   ==             M[                                  A]
|6<<27<rand()||!C&!Z?J[M[E]=M[A]]=E,J[M[A]=A-Z]=A,"_.":" |"];}