ust iterate over the locator... (#2031)

servers/src/common/adapters.rs

@@ -408,40 +408,18 @@ impl NetToChainAdapter {
 			.expect("Failed to upgrade weak ref to our chain.")
 	}
 
-	// recursively go back through the locator vector and stop when we find
-	// a header that we recognize this will be a header shared in common
-	// between us and the peer
+	// Find the first locator hash that refers to a known header on our main chain.
 	fn find_common_header(&self, locator: Vec<Hash>) -> Option<BlockHeader> {
-		if locator.len() == 0 {
-			return None;
-		}
-
-		let known = self.chain().get_block_header(&locator[0]);
-
-		match known {
-			Ok(header) => {
-				// even if we know the block, it may not be on our winning chain
-				let known_winning = self.chain().get_header_by_height(header.height);
-				if let Ok(known_winning) = known_winning {
-					if known_winning.hash() != header.hash() {
-						self.find_common_header(locator[1..].to_vec())
-					} else {
-						Some(header)
+		for hash in locator {
+			if let Ok(header) = self.chain().get_block_header(&hash) {
+				if let Ok(header_at_height) = self.chain().get_header_by_height(header.height) {
+					if header.hash() == header_at_height.hash() {
+						return Some(header);
 					}
-				} else {
-					self.find_common_header(locator[1..].to_vec())
 				}
 			}
-			Err(e) => match e.kind() {
-				chain::ErrorKind::StoreErr(store::Error::NotFoundErr(_), _) => {
-					self.find_common_header(locator[1..].to_vec())
-				}
-				_ => {
-					error!("Could not build header locator: {:?}", e);
-					None
-				}
-			},
 		}
+		None
 	}
 
 	// pushing the new block through the chain pipeline