make editor_chat robust against empty payload (might as well assume the worst)
make editor_chat robust against empty payload (might as well assume the worst)

tscholl2/smc,tscholl2/smc,tscholl2/smc,tscholl2/smc,tscholl2/smc,sagemathinc/smc,DrXyzzy/smc,sagemathinc/smc,DrXyzzy/smc,sagemathinc/smc,DrXyzzy/smc,DrXyzzy/smc,sagemathinc/smc