Test.

ethcore/src/blockchain/blockchain.rs

@@ -874,6 +874,44 @@ mod tests {
 		assert_eq!(bc.ancestry_iter(block_hashes[0].clone()).unwrap().collect::<Vec<_>>(), block_hashes)
 	}
 
+	#[test]
+	#[cfg_attr(feature="dev", allow(cyclomatic_complexity))]
+	fn test_find_uncles() {
+		let mut canon_chain = ChainGenerator::default();
+		let mut finalizer = BlockFinalizer::default();
+		let genesis = canon_chain.generate(&mut finalizer).unwrap();
+		let b1b = canon_chain.fork(1).generate(&mut finalizer.fork()).unwrap();
+		let b1a = canon_chain.generate(&mut finalizer).unwrap();
+		let b2b = canon_chain.fork(1).generate(&mut finalizer.fork()).unwrap();
+		let b2a = canon_chain.generate(&mut finalizer).unwrap();
+		let b3b = canon_chain.fork(1).generate(&mut finalizer.fork()).unwrap();
+		let b3a = canon_chain.generate(&mut finalizer).unwrap();
+		let b4b = canon_chain.fork(1).generate(&mut finalizer.fork()).unwrap();
+		let b4a = canon_chain.generate(&mut finalizer).unwrap();
+		let b5b = canon_chain.fork(1).generate(&mut finalizer.fork()).unwrap();
+		let b5a = canon_chain.generate(&mut finalizer).unwrap();
+
+		let temp = RandomTempPath::new();
+		let bc = BlockChain::new(BlockChainConfig::default(), &genesis, temp.as_path());
+		bc.insert_block(&b1a, vec![]);
+		bc.insert_block(&b1b, vec![]);
+		bc.insert_block(&b2a, vec![]);
+		bc.insert_block(&b2b, vec![]);
+		bc.insert_block(&b3a, vec![]);
+		bc.insert_block(&b3b, vec![]);
+		bc.insert_block(&b4a, vec![]);
+		bc.insert_block(&b4b, vec![]);
+		bc.insert_block(&b5a, vec![]);
+		bc.insert_block(&b5b, vec![]);
+
+		assert_eq!(
+			[&b4b, &b3b, &b2b].iter().map(|b| BlockView::new(b).header()).collect::<Vec<_>>(),
+			bc.find_uncle_headers(&BlockView::new(&b4a).header_view().sha3(), 3).unwrap()
+		);
+
+		// TODO: insert block that already includes one of them as an uncle to check it's not allowed.
+	}
+
 	#[test]
 	#[cfg_attr(feature="dev", allow(cyclomatic_complexity))]
 	fn test_small_fork() {

ethcore/src/header.rs

@@ -29,7 +29,7 @@ pub type BlockNumber = u64;
 /// which is non-specific.
 ///
 /// Doesn't do all that much on its own.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Eq)]
 pub struct Header {
 	// TODO: make all private.
 	/// Parent hash.
@@ -70,6 +70,25 @@ pub struct Header {
 	pub bare_hash: RefCell<Option<H256>>,
 }
 
+impl PartialEq for Header {
+	fn eq(&self, c: &Header) -> bool {
+		self.parent_hash == c.parent_hash &&
+		self.timestamp == c.timestamp &&
+		self.number == c.number &&
+		self.author == c.author &&
+		self.transactions_root == c.transactions_root &&
+		self.uncles_hash == c.uncles_hash &&
+		self.extra_data == c.extra_data &&
+		self.state_root == c.state_root &&
+		self.receipts_root == c.receipts_root &&
+		self.log_bloom == c.log_bloom &&
+		self.gas_used == c.gas_used &&
+		self.gas_limit == c.gas_limit &&
+		self.difficulty == c.difficulty &&
+		self.seal == c.seal
+	}
+}
+
 impl Default for Header {
 	fn default() -> Self {
 		Header {