createdb: Fix quoting of --encoding, --lc-ctype and --lc-collate

The original coding failed to properly quote those arguments, leading to
failures when using quotes in the values used.  As the quoting can be
encoding-sensitive, the connection to the backend needs to be taken
before applying the correct quoting.

Author: Michael Paquier
Reviewed-by: Daniel Gustafsson
Discussion: https://postgr.es/m/20200214041004.GB1998@paquier.xyz
Backpatch-through: 9.5

src/bin/scripts/createdb.c

@@ -176,6 +176,13 @@ main(int argc, char *argv[])
 			dbname = get_user_name_or_exit(progname);
 	}
 
+	/* No point in trying to use postgres db when creating postgres db. */
+	if (maintenance_db == NULL && strcmp(dbname, "postgres") == 0)
+		maintenance_db = "template1";
+
+	conn = connectMaintenanceDatabase(maintenance_db, host, port, username,
+									  prompt_password, progname, echo);
+
 	initPQExpBuffer(&sql);
 
 	appendPQExpBuffer(&sql, "CREATE DATABASE %s",
@@ -186,23 +193,25 @@ main(int argc, char *argv[])
 	if (tablespace)
 		appendPQExpBuffer(&sql, " TABLESPACE %s", fmtId(tablespace));
 	if (encoding)
-		appendPQExpBuffer(&sql, " ENCODING '%s'", encoding);
+	{
+		appendPQExpBufferStr(&sql, " ENCODING ");
+		appendStringLiteralConn(&sql, encoding, conn);
+	}
 	if (template)
 		appendPQExpBuffer(&sql, " TEMPLATE %s", fmtId(template));
 	if (lc_collate)
-		appendPQExpBuffer(&sql, " LC_COLLATE '%s'", lc_collate);
+	{
+		appendPQExpBufferStr(&sql, " LC_COLLATE ");
+		appendStringLiteralConn(&sql, lc_collate, conn);
+	}
 	if (lc_ctype)
-		appendPQExpBuffer(&sql, " LC_CTYPE '%s'", lc_ctype);
+	{
+		appendPQExpBufferStr(&sql, " LC_CTYPE ");
+		appendStringLiteralConn(&sql, lc_ctype, conn);
+	}
 
 	appendPQExpBufferChar(&sql, ';');
 
-	/* No point in trying to use postgres db when creating postgres db. */
-	if (maintenance_db == NULL && strcmp(dbname, "postgres") == 0)
-		maintenance_db = "template1";
-
-	conn = connectMaintenanceDatabase(maintenance_db, host, port, username,
-									  prompt_password, progname, echo);
-
 	if (echo)
 		printf("%s\n", sql.data);
 	result = PQexec(conn, sql.data);

src/bin/scripts/t/020_createdb.pl

@@ -3,7 +3,7 @@ use warnings;
 
 use PostgresNode;
 use TestLib;
-use Test::More tests => 13;
+use Test::More tests => 22;
 
 program_help_ok('createdb');
 program_version_ok('createdb');
@@ -24,3 +24,27 @@ $node->issues_sql_like(
 
 $node->command_fails([ 'createdb', 'foobar1' ],
 	'fails if database already exists');
+
+# Check quote handling with incorrect option values.
+$node->command_checks_all(
+	[ 'createdb', '--encoding', "foo'; SELECT '1", 'foobar2' ],
+	1,
+	[qr/^$/],
+	[qr/^createdb: error: "foo'; SELECT '1" is not a valid encoding name/s],
+	'createdb with incorrect --lc-collate');
+$node->command_checks_all(
+	[ 'createdb', '--lc-collate', "foo'; SELECT '1", 'foobar2' ],
+	1,
+	[qr/^$/],
+	[
+		qr/^createdb: error: database creation failed: ERROR:  invalid locale name/s
+	],
+	'createdb with incorrect --lc-collate');
+$node->command_checks_all(
+	[ 'createdb', '--lc-ctype', "foo'; SELECT '1", 'foobar2' ],
+	1,
+	[qr/^$/],
+	[
+		qr/^createdb: error: database creation failed: ERROR:  invalid locale name/s
+	],
+	'createdb with incorrect --lc-ctype');