Backport PG12>= fixes from upstream.
Commits:
 - 2be35a64b0143cb8648f44ed4745bfddfeb96e55
 - 4ee79572296a8b3ca234c9521391bac86a18ec59

Description: 'relhasoids' was dropped in PG12 and that caused issues with predefined queries in odbc.

Resolves: #2061312

--- a/configure.ac	2018-05-19 12:43:56.000000000 +0200
+++ b/configure.ac	2022-03-24 15:45:03.420713295 +0100
@@ -138,7 +138,7 @@
 
 if test "$with_libpq" != yes; then
 	if test -d "$with_libpq"; then
-		PATH="$PATH:$with_libpq/bin"
+		PATH="$with_libpq/bin:$PATH"
 		CPPFLAGS="$CPPFLAGS -I$with_libpq/include -I$with_libpq/include/postgresql/internal"
 		LDFLAGS="$LDFLAGS -L$with_libpq/lib"
 	else
--- a/info.c	2018-05-19 12:32:53.000000000 +0200
+++ b/info.c	2022-03-24 15:44:11.294453181 +0100
@@ -2341,9 +2341,11 @@
 		"t.typname, a.attnum, a.attlen, a.atttypmod, a.attnotnull, "
 		"c.relhasrules, c.relkind, c.oid, pg_get_expr(d.adbin, d.adrelid), "
         "case t.typtype when 'd' then t.typbasetype else 0 end, t.typtypmod, "
-        "c.relhasoids, %s, c.relhassubclass "
+        "%s, %s, c.relhassubclass "
 		"from (((pg_catalog.pg_class c "
-		"inner join pg_catalog.pg_namespace n on n.oid = c.relnamespace", PG_VERSION_GE(conn, 10.0) ? "attidentity" : "''");
+		"inner join pg_catalog.pg_namespace n on n.oid = c.relnamespace",
+            PG_VERSION_GE(conn, 12.0) ? "0" : "c.relhasoids",
+            PG_VERSION_GE(conn, 10.0) ? "attidentity" : "''");
 	if (search_by_ids)
 		appendPQExpBuffer(&columns_query, " and c.oid = %u", reloid);
 	else
@@ -2857,7 +2859,12 @@
 	/*
 	 * Create the query to find out if this is a view or not...
 	 */
-	appendPQExpBufferStr(&columns_query, "select c.relhasrules, c.relkind, c.relhasoids");
+	appendPQExpBufferStr(&columns_query, "select c.relhasrules, c.relkind");
+   if (PG_VERSION_LT(conn, 12.0))
+       appendPQExpBufferStr(&columns_query, ", c.relhasoids");
+   else
+       appendPQExpBufferStr(&columns_query, ", 0 as relhasoids");
+
 	appendPQExpBufferStr(&columns_query, " from pg_catalog.pg_namespace u,"
 					" pg_catalog.pg_class c where "
 					"u.oid = c.relnamespace");
@@ -3243,7 +3250,7 @@
 	initPQExpBuffer(&index_query);
 	printfPQExpBuffer(&index_query, "select c.relname, i.indkey, i.indisunique"
 		", i.indisclustered, a.amname, c.relhasrules, n.nspname"
-		", c.oid, d.relhasoids, %s"
+                ", c.oid, %s, %s"
 		" from pg_catalog.pg_index i, pg_catalog.pg_class c,"
 		" pg_catalog.pg_class d, pg_catalog.pg_am a,"
 		" pg_catalog.pg_namespace n"
@@ -3253,7 +3260,8 @@
 		" and d.oid = i.indrelid"
 		" and i.indexrelid = c.oid"
 		" and c.relam = a.oid order by"
-		, PG_VERSION_GE(conn, 8.3) ? "i.indoption" : "0"
+		, PG_VERSION_LT(conn, 12.0) ? "d.relhasoids" : "0"
+                , PG_VERSION_GE(conn, 8.3) ? "i.indoption" : "0"
 		, eq_string, escTableName, eq_string, escSchemaName);
 	appendPQExpBufferStr(&index_query, " i.indisprimary desc,");
 	appendPQExpBufferStr(&index_query, " i.indisunique, n.nspname, c.relname");
--- a/parse.c	2022-03-24 15:41:07.544536251 +0100
+++ b/parse.c	2022-03-28 12:10:34.656785167 +0200
@@ -379,12 +379,22 @@
 	}
 }
 
-static BOOL CheckHasOidsUsingSaved(StatementClass *stmt, TABLE_INFO *ti)
+/*
+ *	Check relhasoids(before PG12), relhssubclass and get some relevant information.
+ */
+BOOL CheckPgClassInfo(StatementClass *stmt)
 {
 	const COL_INFO *coli;
 	int	table_info;
+	TABLE_INFO	*ti;
 	BOOL	hasoids = FALSE, hassubclass =FALSE, keyFound = FALSE;
 
+MYLOG(0, "Entering\n");
+	if (0 != SC_checked_hasoids(stmt))
+		return TRUE;
+	if (!stmt->ti || !stmt->ti[0])
+		return FALSE;
+	ti = stmt->ti[0];
 	MYLOG(DETAIL_LOG_LEVEL, "ti->col_info=%p\n", ti->col_info);
 	if (TI_checked_hasoids(ti))
 		;
@@ -465,93 +475,6 @@
 	return TRUE;
 }
 
-static BOOL CheckHasOids(StatementClass * stmt)
-{
-	QResultClass	*res;
-	BOOL		hasoids = TRUE, hassubclass =FALSE, foundKey = FALSE;
-	char		query[512];
-	ConnectionClass	*conn = SC_get_conn(stmt);
-	TABLE_INFO	*ti;
-
-MYLOG(0, "Entering\n");
-	if (0 != SC_checked_hasoids(stmt))
-		return TRUE;
-	if (!stmt->ti || !stmt->ti[0])
-		return FALSE;
-	ti = stmt->ti[0];
-	if (CheckHasOidsUsingSaved(stmt, ti))
-		return TRUE;
-	// no longer come here??
-	SPRINTF_FIXED(query,
-			 "select relhasoids, c.oid, relhassubclass from pg_class c, pg_namespace n where relname = '%s' and nspname = '%s' and c.relnamespace = n.oid",
-			 SAFE_NAME(ti->table_name), SAFE_NAME(ti->schema_name));
-	res = CC_send_query(conn, query, NULL, READ_ONLY_QUERY, NULL);
-	if (QR_command_maybe_successful(res))
-	{
-		stmt->num_key_fields = PG_NUM_NORMAL_KEYS;
-		if (1 == QR_get_num_total_tuples(res))
-		{
-			const char *value = QR_get_value_backend_text(res, 0, 0);
-			const char *value2 = QR_get_value_backend_text(res, 0, 2);
-			if (value && ('f' == *value || '0' == *value))
-			{
-				hasoids = FALSE;
-				TI_set_has_no_oids(ti);
-			}
-			else
-			{
-				TI_set_hasoids(ti);
-				foundKey = TRUE;
-				STR_TO_NAME(ti->bestitem, OID_NAME);
-				STRX_TO_NAME(ti->bestqual, "\"" OID_NAME "\" = %u");
-			}
-			if (value2 && ('f' == *value2 || '0' == *value2))
-			{
-				TI_set_has_no_subclass(ti);
-			}
-			else
-			{
-				hassubclass = TRUE;
-				TI_set_hassubclass(ti);
-				STR_TO_NAME(ti->bestitem, TABLEOID_NAME);
-				STRX_TO_NAME(ti->bestqual, "\"" TABLEOID_NAME "\" = %u");
-			}
-			TI_set_hasoids_checked(ti);
-			ti->table_oid = (OID) strtoul(QR_get_value_backend_text(res, 0, 1), NULL, 10);
-		}
-		QR_Destructor(res);
-		res = NULL;
-		if (!hasoids && !hassubclass)
-		{
-			SPRINTF_FIXED(query, "select a.attname, a.atttypid from pg_index i, pg_attribute a where indrelid=%u and indnatts=1 and indisunique and indexprs is null and indpred is null and i.indrelid = a.attrelid and a.attnum=i.indkey[0] and attnotnull and atttypid in (%d, %d)", ti->table_oid, PG_TYPE_INT4, PG_TYPE_OID);
-			res = CC_send_query(conn, query, NULL, READ_ONLY_QUERY, NULL);
-			if (QR_command_maybe_successful(res) && QR_get_num_total_tuples(res) > 0)
-			{
-				foundKey = TRUE;
-				STR_TO_NAME(ti->bestitem, QR_get_value_backend_text(res, 0, 0));
-				SPRINTF_FIXED(query, "\"%s\" = %%", SAFE_NAME(ti->bestitem));
-				if (PG_TYPE_INT4 == (OID) QR_get_value_backend_int(res, 0, 1, NULL))
-					STRCAT_FIXED(query, "d");
-				else
-					STRCAT_FIXED(query, "u");
-				STRX_TO_NAME(ti->bestqual, query);
-			}
-			else
-			{
-				/* stmt->updatable = FALSE; */
-				foundKey = TRUE;
-				stmt->num_key_fields--;
-			}
-		}
-	}
-	QR_Destructor(res);
-	SC_set_checked_hasoids(stmt, foundKey);
-
-	MYLOG(DETAIL_LOG_LEVEL, "subclass=%d oids=%d bestqual=%s foundKey=%d num_key_fields=%d\n", TI_has_subclass(ti), TI_has_oids(ti), PRINT_NAME(ti->bestqual), foundKey, stmt->num_key_fields);
-
-	return TRUE;
-}
-
 static BOOL increaseNtab(StatementClass *stmt, const char *func)
 {
 	TABLE_INFO	**ti = stmt->ti, *wti;
@@ -1383,7 +1304,7 @@
 	if (SC_parsed_status(stmt) != STMT_PARSE_NONE)
 	{
 		if (check_hasoids)
-			CheckHasOids(stmt);
+			CheckPgClassInfo(stmt);
 		return TRUE;
 	}
 	nfields = 0;
@@ -2261,7 +2182,7 @@
 	}
 
 	if (check_hasoids && updatable)
-		CheckHasOids(stmt);
+		CheckPgClassInfo(stmt);
 	SC_set_parse_status(stmt, parse ? STMT_PARSE_COMPLETE : STMT_PARSE_INCOMPLETE);
 	for (i = 0; i < (int) irdflds->nfields; i++)
 	{
--- a/statement.h	2018-05-19 12:32:53.000000000 +0200
+++ b/statement.h	2022-03-28 12:11:20.015023357 +0200
@@ -542,6 +542,7 @@
 RETCODE		DiscardStatementSvp(StatementClass *self, RETCODE, BOOL errorOnly);
 
 QResultClass *ParseAndDescribeWithLibpq(StatementClass *stmt, const char *plan_name, const char *query_p, Int2 num_params, const char *comment, QResultClass *res);
+BOOL	CheckPgClassInfo(StatementClass *);
 
 /*
  *	Macros to convert global index <-> relative index in resultset/rowset