pgsql: Throw error when assigning jsonb scalar instead of a composite o

Throw error when assigning jsonb scalar instead of a composite object

During the jsonb subscripting assignment, the provided path might assume an
object or an array where the source jsonb has a scalar value. Initial
subscripting assignment logic will skip such an update operation with no
message shown. This commit makes it throw an error to indicate this type
of situation.

Discussion: https://postgr.es/m/CA%2Bq6zcV8qvGcDXurwwgUbwACV86Th7G80pnubg42e-p9gsSf%3Dg%40mail.gmail.com
Discussion: https://postgr.es/m/CA%2Bq6zcX3mdxGCgdThzuySwH-ApyHHM-G4oB1R0fn0j2hZqqkLQ%40mail.gmail.com
Discussion: https://postgr.es/m/CA%2Bq6zcVDuGBv%3DM0FqBYX8DPebS3F_0KQ6OVFobGJPM507_SZ_w%40mail.gmail.com
Discussion: https://postgr.es/m/CA%2Bq6zcVovR%2BXY4mfk-7oNk-rF91gH0PebnNfuUjuuDsyHjOcVA%40mail.gmail.com
Author: Dmitry Dolgov
Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
Reviewed-by: Andrew Dunstan, Chapman Flack, Merlin Moncure, Peter Geoghegan
Reviewed-by: Alvaro Herrera, Jim Nasby, Josh Berkus, Victor Wagner
Reviewed-by: Aleksander Alekseev, Robert Haas, Oleg Bartunov

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/aa6e46daf5304e8d9e66fefc1a5bd77622ec6402

Modified Files
--------------
doc/src/sgml/json.sgml | 39 +++++++++++++++++++++++++++++--------
src/backend/utils/adt/jsonfuncs.c | 29 +++++++++++++++++++++++++++
src/test/regress/expected/jsonb.out | 27 +++++++++++++++++++++++++
src/test/regress/sql/jsonb.sql | 17 ++++++++++++++++
4 files changed, 104 insertions(+), 8 deletions(-)