Add pg_update C comment about problems with plpython_call_handler().

diff --git a/contrib/pg_upgrade/function.c b/contrib/pg_upgrade/function.c
index fe8fb408cd21c444073f2450652061d3c1d7cbf9..e38071ed95f5ced95eab0f3fd4a0d87bf8fba93d 100644 (file)
--- a/contrib/pg_upgrade/function.c
+++ b/contrib/pg_upgrade/function.c
@@ -240,6 +240,12 @@ check_loadable_libraries(void)
                 *      For this case, we could check pg_pltemplate, but that only works
                 *      for languages, and does not help with function shared objects,
                 *      so we just do a general fix.
+                *
+                *      Some systems have plpython_call_handler() that references
+                *      "plpython" defined in the "public" schema, causing pg_dump to
+                *      dump it an generate an error on pg_dumpall restore;  not sure
+                *      on the cause, see:
+                *      http://archives.postgresql.org/pgsql-hackers/2012-03/msg01101.php
                 */
                if (GET_MAJOR_VERSION(old_cluster.major_version) < 901 &&
                        strcmp(lib, "$libdir/plpython") == 0)