pow: fix Search with ethash test mode

The cache/dataset methods crashed with a nil pointer error if
cachesinmem/dagsinmem were zero. Fix it by skipping the eviction logic
if there are no caches/datasets.

Search always used the regular dataset size regardless of test mode. Fix
it by removing the redundant size parameter of hashimotoFull.

Fixes #3784

1 files changed, 2 insertions, 2 deletions

diff --git a/pow/ethash_algo.go b/pow/ethash_algo.go
index 3737cc5d7..1e996785f 100644
--- a/pow/ethash_algo.go
+++ b/pow/ethash_algo.go
@@ -349,12 +349,12 @@ func hashimotoLight(size uint64, cache []uint32, hash []byte, nonce uint64) ([]b
 // hashimotoFull aggregates data from the full dataset (using the full in-memory
 // dataset) in order to produce our final value for a particular header hash and
 // nonce.
-func hashimotoFull(size uint64, dataset []uint32, hash []byte, nonce uint64) ([]byte, []byte) {
+func hashimotoFull(dataset []uint32, hash []byte, nonce uint64) ([]byte, []byte) {
 	lookup := func(index uint32) []uint32 {
 		offset := index * hashWords
 		return dataset[offset : offset+hashWords]
 	}
-	return hashimoto(hash, nonce, size, lookup)
+	return hashimoto(hash, nonce, uint64(len(dataset))*4, lookup)
 }
 
 // datasetSizes is a lookup table for the ethash dataset size for the first 2048