From 09f5e301d226d3eac1c6f28d569c6f791d31097e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Mah=C3=A9?= <frederic.mahe@cirad.fr>
Date: Thu, 2 Jan 2025 18:55:04 +0100
Subject: [PATCH] comment

---
 src/derep_prefix.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/derep_prefix.cc b/src/derep_prefix.cc
index 5712f371..524e40c5 100644
--- a/src/derep_prefix.cc
+++ b/src/derep_prefix.cc
@@ -100,6 +100,7 @@ auto derep_compare_prefix(const void * a, const void * b) -> int
       return -1;
     }
 
+  // both are deleted, compare abundances
   if (lhs->size < rhs->size)
     {
       return +1;
@@ -109,6 +110,7 @@ auto derep_compare_prefix(const void * a, const void * b) -> int
       return -1;
     }
 
+  // both are deleted, same abundances, compare sequence headers
   auto const result = std::strcmp(db_getheader(lhs->seqno_first),
                                   db_getheader(rhs->seqno_first));
   if (result != 0)
@@ -116,6 +118,7 @@ auto derep_compare_prefix(const void * a, const void * b) -> int
       return result;
     }
 
+  // both are deleted, same abundances, same sequence headers, compare input order
   if (lhs->seqno_first < rhs->seqno_first)
     {
       return -1;