pg_upgrade: Fix inconsistency in memory freeing

The function in charge of freeing the memory from a result created by
PQescapeIdentifier() has to be PQfreemem(), to ensure that both
allocation and free come from libpq.

One spot in pg_upgrade was not respecting that for pg_database's
datlocale (daticulocale in v16) when the collation provider is libc (aka
datlocale/daticulocale is NULL) with an allocation done using
pg_strdup() and a free with PQfreemem().  The code is changed to always
use PQescapeLiteral() when processing the input.

Oversight in 9637badd9f92.  This commit is similar to 48e4ae9a0707 and
5b94e2753439.

Author: Michael Paquier <michael@paquier.xyz>
Co-authored-by: Ranier Vilela <ranier.vf@gmail.com>
Discussion: https://postgr.es/m/Z601RQxTmIUohdkV@paquier.xyz
Backpatch-through: 16

diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index d95c491fb57e705b40521c9f615f0acfd5a15f42..174cd920840cb18f139ed52b937c5a03ee291a24 100644 (file)
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -437,6 +437,7 @@ set_locale_and_encoding(void)
    char       *datcollate_literal;
    char       *datctype_literal;
    char       *datlocale_literal = NULL;
+   char       *datlocale_src;
    DbLocaleInfo *locale = old_cluster.template0;
 
    prep_status("Setting locale and encoding for new cluster");
@@ -450,12 +451,10 @@ set_locale_and_encoding(void)
    datctype_literal = PQescapeLiteral(conn_new_template1,
                                       locale->db_ctype,
                                       strlen(locale->db_ctype));
-   if (locale->db_locale)
-       datlocale_literal = PQescapeLiteral(conn_new_template1,
-                                           locale->db_locale,
-                                           strlen(locale->db_locale));
-   else
-       datlocale_literal = pg_strdup("NULL");
+   datlocale_src = locale->db_locale ? locale->db_locale : "NULL";
+   datlocale_literal = PQescapeLiteral(conn_new_template1,
+                                       datlocale_src,
+                                       strlen(datlocale_src));
 
    /* update template0 in new cluster */
    if (GET_MAJOR_VERSION(new_cluster.major_version) >= 1700)