.gitattributes

# Pack files are maps, not text (PACK-SPEC.md). git's line merge can apply two
# branches' insertions of the SAME entry key at different anchors and leave the
# key in the file twice, which is not valid pack storage - pkg/pack refuses it and
# metafmt cannot re-render it. scripts/pack-union-merge.sh merges the entry maps
# instead, with the same three-way rules a person would apply, so name it here as
# the merge driver for the data tree.
#
# A driver only runs where it is configured, which keeps this additive: the intake
# sweep (.github/workflows/intake.yml) configures it, a contributor can with
#
#   git config merge.packjson.name "three-way merge of pack-file entries"
#   git config merge.packjson.driver "scripts/pack-union-merge.sh %O %A %B %P"
#
# and any checkout that has not falls back to git's own line merge exactly as
# before.
/data/**/*.json merge=packjson

# data/redirects.json is NOT a pack (it is the slug tombstone table, one small
# map of retired slug -> live slug), so the pack driver above must not be handed
# it. The driver refuses any file with no top-level "entries" object, so being
# handed it would leave the conflict unresolved - where git's own line merge
# resolves the common case and stops loudly on the rest. Unsetting the attribute
# restores that default for this one path.
/data/redirects.json !merge