pgsql: postmaster: Don't repeatedly transition to crashing state

postmaster: Don't repeatedly transition to crashing state

Previously HandleChildCrash() skipped logging and signalling child exits if
already in an immediate shutdown or in FatalError state, but still
transitioned server state in response to a crash. That's redundant.

In the other place we transition to FatalError, we do take care to not do so
when already in FatalError state.

To make it easier to combine different paths for entering FatalError state,
only do so once in HandleChildCrash().

Reviewed-by: Bertrand Drouvot <bertranddrouvot(dot)pg(at)gmail(dot)com>
Discussion: https://postgr.es/m/kgng5nrvnlv335evmsuvpnh354rw7qyazl73kdysev2cr2v5zu@m3cfzxicm5kp

Branch
------
master

Details
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https://git.postgresql.org/pg/commitdiff/f0b7ab7251390544c5e79d1d9c96da254181fc4f

Modified Files
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src/backend/postmaster/postmaster.c | 22 ++++++++--------------
1 file changed, 8 insertions(+), 14 deletions(-)