set tail height to include genesis (#3773)

Author: yeastplume

api/src/handlers/blocks_api.rs

@@ -152,11 +152,18 @@ impl BlockHandler {
 			max = BLOCK_TRANSFER_LIMIT;
 		}
 		let tail_height = self.get_tail_height()?;
+		let orig_start_height = start_height;
 
 		if start_height < tail_height {
 			start_height = tail_height;
 		}
 
+		// In full archive node, tail will be set to 1, so include genesis block as well
+		// for consistency
+		if start_height == 1 && orig_start_height == 0 {
+			start_height = 0;
+		}
+
 		let mut result_set = BlockListing {
 			last_retrieved_height: 0,
 			blocks: vec![],