Use escape strings for version regexes

Make the PostGIS script-version comparison helper and its regression checks independent of standard_conforming_strings. This avoids warnings during install when standard_conforming_strings is off, which the regression harness treats as load failure.\n\nCloses #2808

Author: Komzpa

postgis/postgis.sql.in

@@ -3161,7 +3161,7 @@ CREATE OR REPLACE FUNCTION _postgis_scripts_version_cmp_key(ver text)
 	BEGIN
 		ver_match := pg_catalog.regexp_match(
 			pg_catalog.lower(ver),
-			'^([0-9]+)\.([0-9]+)\.([0-9]+)(dev|alpha|beta|rc)?([0-9]*)([^0-9a-z].*)?$'
+			E'^([0-9]+)\\.([0-9]+)\\.([0-9]+)(dev|alpha|beta|rc)?([0-9]*)([^0-9a-z].*)?$'
 		);
 		IF ver_match IS NULL THEN
 			RETURN NULL;

regress/core/postgis_full_version.sql

@@ -25,7 +25,7 @@ LANGUAGE 'sql' IMMUTABLE;
 -- Older component script versions still mean the installed procs need upgrade.
 SELECT 'topology_old_scripts',
 	postgis_full_version() ~
-		'TOPOLOGY \(topology procs from "1\.0\.0" need upgrade\)';
+		E'TOPOLOGY \\(topology procs from "1\\.0\\.0" need upgrade\\)';
 
 CREATE OR REPLACE FUNCTION topology.postgis_topology_scripts_installed()
 RETURNS text
@@ -52,17 +52,17 @@ LANGUAGE 'sql' IMMUTABLE;
 -- includes final releases newer than release candidates and later RCs.
 SELECT 'topology_newer_scripts',
 	postgis_full_version() ~
-		'TOPOLOGY \(topology procs from "3\.7\.0" are newer than core procs from "3\.7\.0rc1"\)';
+		E'TOPOLOGY \\(topology procs from "3\\.7\\.0" are newer than core procs from "3\\.7\\.0rc1"\\)';
 
 SELECT 'raster_newer_scripts',
 	postgis_full_version() ~
-		'\(raster procs from "3\.7\.0rc2" are newer than core procs from "3\.7\.0rc1"\)';
+		E'\\(raster procs from "3\\.7\\.0rc2" are newer than core procs from "3\\.7\\.0rc1"\\)';
 
 -- A prerelease older than the core prerelease is still reported as needing
 -- upgrade, even when its numeric major/minor/micro components match.
 SELECT 'sfcgal_older_prerelease',
 	postgis_full_version() ~
-		'\(sfcgal procs from "3\.7\.0beta1" need upgrade\)';
+		E'\\(sfcgal procs from "3\\.7\\.0beta1" need upgrade\\)';
 
 CREATE OR REPLACE FUNCTION postgis_sfcgal_scripts_installed()
 RETURNS text
@@ -71,6 +71,6 @@ LANGUAGE 'sql' IMMUTABLE;
 
 SELECT 'sfcgal_newer_scripts',
 	postgis_full_version() ~
-		'\(sfcgal procs from "3\.7\.0" are newer than core procs from "3\.7\.0rc1"\)';
+		E'\\(sfcgal procs from "3\\.7\\.0" are newer than core procs from "3\\.7\\.0rc1"\\)';
 
 ROLLBACK;