Add a comment about a puzzling piece of code

The trick to store the same string only once is not clear and deserves a
little comment.

diff --git a/userinfo.c b/userinfo.c
index e9338616fba518efc36b1da31ca86d6454a04887..89be0ddbb552e766968861c4176c98c8ccaabc55 100644 (file)
--- a/userinfo.c
+++ b/userinfo.c
@@ -111,9 +111,16 @@ struct userinfostruct *userinfo_create(const char *userid,const char *ip)
        }
        user->label=user->id; //assign a label to avoid a NULL pointer in case none is provided
        if (ip) {
+               /*
+                * IP address is not the same as the user's ID. A separate buffer
+                * must be allocated.
+                */
                user->id_is_ip=false;
                user->ip=StringBuffer_Store(UserStrings,ip);
        } else {
+               /*
+                * User's IP address share the same buffer as the user's ID.
+                */
                user->id_is_ip=true;
                user->ip=user->id;
        }