Suppress default-prevented composition events on compositionstart
Suppress default-prevented composition events on compositionstart

This avoids creating a composition checkpoint and reverting to it on the
next keystroke, which causes the cursor to move.

liuderchi/atom,atom/atom,Arcanemagus/atom,FIT-CSE2410-A-Bombs/atom,PKRoma/atom,andrewleverette/atom,stinsonga/atom,stinsonga/atom,Mokolea/atom,t9md/atom,t9md/atom,andrewleverette/atom,Mokolea/atom,FIT-CSE2410-A-Bombs/atom,FIT-CSE2410-A-Bombs/atom,Mokolea/atom,andrewleverette/atom,atom/atom,Arcanemagus/atom,liuderchi/atom,kevinrenaers/atom,ardeshirj/atom,liuderchi/atom,ardeshirj/atom,brettle/atom,PKRoma/atom,brettle/atom,Arcanemagus/atom,kevinrenaers/atom,ardeshirj/atom,stinsonga/atom,liuderchi/atom,t9md/atom,kevinrenaers/atom,PKRoma/atom,stinsonga/atom,atom/atom,brettle/atom