Thread: pgsql: Fix initdb's -c option to treat the GUC name case-insensitively.

Fix initdb's -c option to treat the GUC name case-insensitively.

The backend treats GUC names case-insensitively, so this code should
too.  This avoids ending up with a confusing set of redundant entries
in the generated postgresql.conf file.

Per report from Kyotaro Horiguchi.  Back-patch to v16 where this
feature was added (in commit 3e51b278d).

Discussion: https://postgr.es/m/20230928.164904.2153358973162534034.horikyota.ntt@gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/fce2ce797c412df8b794b8a92c5a586db5e1bedc

Modified Files
--------------
src/bin/initdb/initdb.c        |  9 +++++++--
src/bin/initdb/t/001_initdb.pl | 14 ++++++++++++++
2 files changed, 21 insertions(+), 2 deletions(-)