  A possible effect of direct CP violation in D->K0Spipi decay on the gamma
measurement from B->DK, D->K0Spi+pi- Dalitz plot analysis is considered.
Systematic uncertainty of gamma coming from the current limits on direct CP
violation in D->K0Spi+pi- is estimated, and a modified model-independent
procedure of B->DK, D->K0Spi+pi- Dalitz plot analysis is proposed that gives an
unbiased gamma measurement even in presence of direct CP violation in charm
decays. The technique is applicable to other three-body D decays such as
D->K0SK+K-, D->pi+pi-pi0, etc.
