-SELECT convert_from(CAST(E'\\x' || string_agg(CASE WHEN length(r.m[1]) = 1 THEN encode(convert_to(r.m[1], 'SQL_ASCII'), 'hex') ELSE substring(r.m[1] from 2 for 2) END, '') AS bytea), 'UTF8')
-FROM regexp_matches($1, '%[0-9a-f][0-9a-f]|.', 'gi') AS r(m);
+SELECT convert_from(CAST(E'\\x' || array_to_string(ARRAY(
+ SELECT CASE WHEN length(r.m[1]) = 1 THEN encode(convert_to(r.m[1], 'SQL_ASCII'), 'hex') ELSE substring(r.m[1] from 2 for 2) END
+ FROM regexp_matches($1, '%[0-9a-f][0-9a-f]|.', 'gi') AS r(m)
+), '') AS bytea), 'UTF8');