pgsql: Prohibit altering invalidated replication slots.

Prohibit altering invalidated replication slots.

ALTER_REPLICATION_SLOT for invalid replication slots should not be allowed
because there is no way to get back the invalidated (logical) slot to
work.

Author: Bharath Rupireddy
Reviewed-by: Peter Smith, Shveta Malik
Discussion: https://www.postgresql.org/message-id/CALj2ACW4fSOMiKjQ3=2NVBMTZRTG8Ujg6jsK9z3EvOtvA4vzKQ@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/4d8489f4f1fa86a99e6db0ea702911e1cf92fa81

Modified Files
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src/backend/replication/slot.c                      |  7 +++++++
src/test/recovery/t/035_standby_logical_decoding.pl | 12 +++++++++++-
2 files changed, 18 insertions(+), 1 deletion(-)