core: ensure the canonical block is written before the canonical hash is set

core/blockchain_test.go

@@ -1090,3 +1090,41 @@ done:
 	}
 
 }
+
+// Tests if the canonical block can be fetched from the database during chain insertion.
+func TestCanonicalBlockRetrieval(t *testing.T) {
+	var (
+		db, _   = ethdb.NewMemDatabase()
+		genesis = WriteGenesisBlockForTesting(db)
+	)
+
+	evmux := &event.TypeMux{}
+	blockchain, _ := NewBlockChain(db, testChainConfig(), FakePow{}, evmux)
+
+	chain, _ := GenerateChain(nil, genesis, db, 10, func(i int, gen *BlockGen) {})
+
+	for i, _ := range chain {
+		go func(block *types.Block) {
+			// try to retrieve a block by its canonical hash and see if the block data can be retrieved.
+			for {
+				ch := GetCanonicalHash(db, block.NumberU64())
+				if ch == (common.Hash{}) {
+					continue // busy wait for canonical hash to be written
+				}
+				if ch != block.Hash() {
+					t.Fatalf("unknown canonical hash, want %s, got %s", block.Hash().Hex(), ch.Hex())
+				}
+				fb := GetBlock(db, ch, block.NumberU64())
+				if fb == nil {
+					t.Fatalf("unable to retrieve block %d for canonical hash: %s", block.NumberU64(), ch.Hex())
+				}
+				if fb.Hash() != block.Hash() {
+					t.Fatalf("invalid block hash for block %d, want %s, got %s", block.NumberU64(), block.Hash().Hex(), fb.Hash().Hex())
+				}
+				return
+			}
+		}(chain[i])
+
+		blockchain.InsertChain(types.Blocks{chain[i]})
+	}
+}