pgsql: Refactor CopyFrom() in copyfrom.c.

Refactor CopyFrom() in copyfrom.c.

This commit simplifies CopyFrom() by removing the unnecessary local variable
'skipped', which tracked the number of rows skipped due to on_error = 'ignore'.
That count is already handled by cstate->num_errors, so the 'skipped' variable
was redundant.

Additionally, the condition on_error != COPY_ON_ERROR_STOP is removed.
Since on_error == COPY_ON_ERROR_IGNORE is already checked, and on_error
only has two values (ignore and stop), the additional check was redundant
and made the logic harder to read. Seemingly this was introduced
in preparation for a future patch, but the current checks don’t offer
clear value and have been removed to improve readability.

Author: Atsushi Torikoshi
Reviewed-by: Masahiko Sawada, Fujii Masao
Discussion: https://postgr.es/m/ab59dad10490ea3734cf022b16c24cfd@oss.nttdata.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/e55f025b059fb02b659f12f3003c160ed4674dc8

Modified Files
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src/backend/commands/copyfrom.c | 21 ++++++++-------------
1 file changed, 8 insertions(+), 13 deletions(-)