In pg_upgrade, report pre-PG 8.1 plpython helper functions left in the

public schema that no longer point to valid shared object libraries, and
suggest a solution.

diff --git a/contrib/pg_upgrade/function.c b/contrib/pg_upgrade/function.c
index 90e8a9f58110c2df49a32c901ae39a2b8466bbcc..b4b17badb28ce8abfa2f946c33572c01f98fa021 100644 (file)
--- a/contrib/pg_upgrade/function.c
+++ b/contrib/pg_upgrade/function.c
@@ -132,7 +132,8 @@ get_loadable_libraries(void)
    PGresult  **ress;
    int         totaltups;
    int         dbnum;
-
+   bool        found_public_plpython_handler = false;
+   
    ress = (PGresult **) pg_malloc(old_cluster.dbarr.ndbs * sizeof(PGresult *));
    totaltups = 0;
 
@@ -157,9 +158,67 @@ get_loadable_libraries(void)
                                        FirstNormalObjectId);
        totaltups += PQntuples(ress[dbnum]);
 
+        /*
+         * Systems that install plpython before 8.1 have
+         * plpython_call_handler() defined in the "public" schema, causing
+         * pg_dumpall to dump it.  However that function still references
+         * "plpython" (no "2"), so it throws an error on restore.  This code
+         * checks for the problem function, reports affected databases to the
+         * user and explains how to remove them.
+         * 8.1 git commit: e0dedd0559f005d60c69c9772163e69c204bac69
+         * http://archives.postgresql.org/pgsql-hackers/2012-03/msg01101.php
+         * http://archives.postgresql.org/pgsql-bugs/2012-05/msg00206.php
+         */
+       if (GET_MAJOR_VERSION(old_cluster.major_version) < 901)
+       {
+           PGresult  *res;
+
+           res = executeQueryOrDie(conn,
+                                   "SELECT 1 "
+                                   "FROM   pg_catalog.pg_proc JOIN pg_namespace "
+                                   "       ON pronamespace = pg_namespace.oid "
+                                   "WHERE proname = 'plpython_call_handler' AND "
+                                   "nspname = 'public' AND "
+                                   "prolang = 13 /* C */ AND "
+                                   "probin = '$libdir/plpython' AND "
+                                   "pg_proc.oid >= %u;",
+                                   FirstNormalObjectId);
+           if (PQntuples(res) > 0)
+           {
+               if (!found_public_plpython_handler)
+               {
+                   pg_log(PG_WARNING,
+          "\nThe old cluster has a \"plpython_call_handler\" function defined\n"
+           "in the \"public\" schema which is a duplicate of the one defined\n"
+           "in the \"pg_catalog\" schema.  You can confirm this by executing\n"
+           "in psql:\n"
+           "\n"
+           "   \\df *.plpython_call_handler\n"
+           "\n"
+           "The \"public\" schema version of this function was created by a\n"
+           "pre-8.1 install of plpython, and must be removed for pg_upgrade\n"
+           "to complete because it references a now-obsolete \"plpython\"\n"
+           "shared object file.  You can remove the \"public\" schema version\n"
+           "of this function by running the following command:\n"
+           "\n"
+           "   DROP FUNCTION public.plpython_call_handler()\n"
+           "\n"
+           "in each affected database:\n"
+           "\n");
+               }
+               pg_log(PG_WARNING, "    %s\n", active_db->db_name);
+               found_public_plpython_handler = true;
+           }
+           PQclear(res);
+       }
+
        PQfinish(conn);
    }
 
+   if (found_public_plpython_handler)
+       pg_log(PG_FATAL,
+          "Remove the problem functions from the old cluster to continue.\n");
+   
    totaltups++;    /* reserve for pg_upgrade_support */
 
    /* Allocate what's certainly enough space */
@@ -245,12 +304,6 @@ 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)