pgsql: Disallow CR and LF in database, role, and tablespace names

Disallow CR and LF in database, role, and tablespace names

Previously, these characters could cause problems when passed through
shell commands, and were flagged with a comment in string_utils.c
suggesting they be rejected in a future major release.

The affected commands are CREATE DATABASE, CREATE ROLE, CREATE TABLESPACE,
ALTER DATABASE RENAME, ALTER ROLE RENAME, and ALTER TABLESPACE RENAME.

Also add a pg_upgrade check to detect these invalid names in clusters
being upgraded from pre-v19 versions, producing a report file listing
any offending objects that must be renamed before upgrading.

Tests have been modified accordingly.

Author: Mahendra Singh Thalor <mahi6run(at)gmail(dot)com>
Reviewed-By: Álvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>
Reviewed-By: Andrew Dunstan <andrew(at)dunslane(dot)net>
Reviewed-By: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Reviewed-By: Nathan Bossart <nathandbossart(at)gmail(dot)com>
Reviewed-By: Srinath Reddy <srinath2133(at)gmail(dot)com>

Discussion: https://postgr.es/m/CAKYtNApkOi4FY0S7+3jpTqnHVyyZ6Tbzhtbah-NBbY-mGsiKAQ@mail.gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/b380a56a3f9556588a89013b765d67947d54f7d0

Modified Files
--------------
src/backend/commands/dbcommands.c | 12 ++++
src/backend/commands/tablespace.c | 12 ++++
src/backend/commands/user.c | 12 ++++
src/bin/pg_dump/t/002_pg_dump.pl | 9 +--
src/bin/pg_dump/t/003_pg_dump_with_server.pl | 16 -----
src/bin/pg_dump/t/010_dump_connstr.pl | 14 ----
src/bin/pg_upgrade/check.c | 79 ++++++++++++++++++++++
src/bin/scripts/t/020_createdb.pl | 12 ++++
src/fe_utils/string_utils.c | 6 --
.../unsafe_tests/expected/alter_system_table.out | 5 ++
.../modules/unsafe_tests/expected/rolenames.out | 4 ++
.../unsafe_tests/sql/alter_system_table.sql | 4 ++
src/test/modules/unsafe_tests/sql/rolenames.sql | 2 +
src/test/regress/expected/tablespace.out | 5 ++
src/test/regress/sql/tablespace.sql | 4 ++
15 files changed, 153 insertions(+), 43 deletions(-)