Guard against drop 0, contig

Author: LuKks

index.js

@@ -609,7 +609,7 @@ module.exports = class Hypercore extends EventEmitter {
     if (bitfield) {
       const contig = this.core.header.contiguousLength
 
-      if (bitfield.start < contig) {
+      if (bitfield.start < contig && !bitfield.drop) {
         this.replicator.onhave(0, contig, bitfield.drop)
       } else {
         this.replicator.onhave(bitfield.start, bitfield.length, bitfield.drop)