1 files changed, 7 insertions, 0 deletions
diff --git a/sql/field.h b/sql/field.h
index 3007e666ba7..d5e2cb25788 100644
--- a/sql/field.h
+++ b/sql/field.h
@@ -1218,6 +1218,13 @@ public:
 
   void make_sort_key(uchar *buff, uint length);
   virtual void make_field(Send_field *);
+
+  /*
+    Some implementations actually may write up to 8 bytes regardless of what
+    size was requested. This is due to the minimum value of the system variable
+    max_sort_length.
+  */
+
   virtual void sort_string(uchar *buff,uint length)=0;
   virtual bool optimize_range(uint idx, uint part);
   virtual void free() {}