commit 76594784c50bca1b09f687e58f17ff27230076be
Author: Jose Arthur Benetasso Villanova <jose.arthur@locaweb.com.br>
Date:   Tue Jan 19 11:50:22 2016 -0200

    Log message

diff --git a/src/backend/libpq/auth.c b/src/backend/libpq/auth.c
index 57c2f48..ac1c785 100644
--- a/src/backend/libpq/auth.c
+++ b/src/backend/libpq/auth.c
@@ -991,6 +991,7 @@ pg_GSS_recvauth(Port *port)
 		return STATUS_ERROR;
 	}
 
+	port->system_user = pstrdup(gbuf.value);
 	ret = check_usermap(port->hba->usermap, port->user_name, gbuf.value,
 						pg_krb_caseins_users);
 
@@ -1291,6 +1292,7 @@ pg_SSPI_recvauth(Port *port)
 		int			retval;
 
 		namebuf = psprintf("%s@%s", accountname, domainname);
+		port->system_user = pstrdup(namebuf);
 		retval = check_usermap(port->hba->usermap, port->user_name, namebuf, true);
 		pfree(namebuf);
 		return retval;
@@ -1561,8 +1563,11 @@ ident_inet_done:
 		pg_freeaddrinfo_all(local_addr.addr.ss_family, la);
 
 	if (ident_return)
+	{
 		/* Success! Check the usermap */
+		port->system_user = pstrdup(ident_user);
 		return check_usermap(port->hba->usermap, port->user_name, ident_user, false);
+	}
 	return STATUS_ERROR;
 }
 
@@ -1609,6 +1614,8 @@ auth_peer(hbaPort *port)
 	}
 
 	strlcpy(ident_user, pw->pw_name, IDENT_USERNAME_MAX + 1);
+	port->system_user = pstrdup(ident_user);
+
 
 	return check_usermap(port->hba->usermap, port->user_name, ident_user, false);
 }
@@ -2124,6 +2131,7 @@ CheckLDAPAuth(Port *port)
 		return STATUS_ERROR;
 	}
 
+	port->system_user = pstrdup(fulluser);
 	pfree(fulluser);
 
 	return STATUS_OK;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index e22d4db..f425808 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -255,7 +255,8 @@ PerformAuthentication(Port *port)
 #endif
 				ereport(LOG,
 						(errmsg("replication connection authorized: user=%s",
-								port->user_name)));
+								port->user_name),
+						port->system_user ? errdetail_log("system_user=%s", port->system_user) : 0));
 		}
 		else
 		{
@@ -269,7 +270,8 @@ PerformAuthentication(Port *port)
 #endif
 				ereport(LOG,
 						(errmsg("connection authorized: user=%s database=%s",
-								port->user_name, port->database_name)));
+								port->user_name, port->database_name),
+						port->system_user ? errdetail_log("system_user=%s", port->system_user) : 0));
 		}
 	}
 
diff --git a/src/include/libpq/libpq-be.h b/src/include/libpq/libpq-be.h
index 5d07b78..448ac36 100644
--- a/src/include/libpq/libpq-be.h
+++ b/src/include/libpq/libpq-be.h
@@ -129,6 +129,7 @@ typedef struct Port
 	int			remote_hostname_errcode;		/* see above */
 	char	   *remote_port;	/* text rep of remote port */
 	CAC_state	canAcceptConnections;	/* postmaster connection status */
+	char	   *system_user;	/* remote user name if available */
 
 	/*
 	 * Information that needs to be saved from the startup packet and passed