fix chunk header size prediction

src/v0.rs

@@ -760,9 +760,10 @@ pub fn serialize<W:binrw::BinWriterExt>(block:&Block,writer:&mut W)->Result<(),b
 			self.0
 				.iter()
 				.enumerate()
-				.map(|(i,range)|
-					range.len()*EVENT_SIZE[i]
-				)
+				.filter_map(|(i,range)|match range.len(){
+					0=>None,
+					other=>Some(other*EVENT_SIZE[i]+size_of::<EventChunkHeader>()),
+				})
 				.sum()
 		}
 	}