eth/downloader: fix rollback issue on short chains

holiman · holiman · commit 9f7b79af00a1 · 2020-08-21T13:36:08.000+02:00
diff --git a/eth/downloader/downloader.go b/eth/downloader/downloader.go
@@ -1502,6 +1502,8 @@ func (d *Downloader) processHeaders(origin uint64, pivot uint64, td *big.Int) er
 					head := chunk[len(chunk)-1].Number.Uint64()
 					if head-rollback > uint64(fsHeaderSafetyNet) {
 						rollback = head - uint64(fsHeaderSafetyNet)
+					} else {
+						rollback = 1
 					}
 				}
 				// Unless we're doing light chains, schedule the headers for associated content retrieval

Original file line number	Diff line number	Diff line change
`@@ -1502,6 +1502,8 @@ func (d Downloader) processHeaders(origin uint64, pivot uint64, td big.Int) er`
`1502`	`1502`	`head := chunk[len(chunk)-1].Number.Uint64()`
`1503`	`1503`	`if head-rollback > uint64(fsHeaderSafetyNet) {`
`1504`	`1504`	`rollback = head - uint64(fsHeaderSafetyNet)`
	`1505`	`+ } else {`
	`1506`	`+ rollback = 1`
`1505`	`1507`	`}`
`1506`	`1508`	`}`
`1507`	`1509`	`// Unless we're doing light chains, schedule the headers for associated content retrieval`