pgsql: Fix crash of xmlconcat(NULL) also backpatched to 8.3 - Mailing list pgsql-committers

Log Message:
-----------
Fix crash of xmlconcat(NULL)

also backpatched to 8.3

Modified Files:
--------------
    pgsql/src/backend/executor:
        execQual.c (r1.236 -> r1.237)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execQual.c?r1=1.236&r2=1.237)
    pgsql/src/test/regress/expected:
        xml.out (r1.22 -> r1.23)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/xml.out?r1=1.22&r2=1.23)
        xml_1.out (r1.23 -> r1.24)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/xml_1.out?r1=1.23&r2=1.24)
    pgsql/src/test/regress/sql:
        xml.sql (r1.16 -> r1.17)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/xml.sql?r1=1.16&r2=1.17)