# Add to /etc/gitconfig on the Forgejo server.
#
# IMPORTANT: also set core.attributesFile so that bare repositories pick up
# the merge driver.  Committed per-repo .gitattributes files are NOT read by
# git merge-tree --write-tree in bare-repo context.
#
#   [core]
#       attributesFile = /etc/gitattributes
#
# and put "*.ifc merge=ifcmerge" in /etc/gitattributes (see gitattributes
# in this directory).
#
# How the merge drivers work
# --------------------------
# The invariant: step-IDs in main/master must never be renumbered, because
# existing cross-references depend on them.  ifcmerge always renumbers the
# "remote" side by default; --prioritise-local reverses this and renumbers
# the "remote" side instead.  The correct driver depends on which branch is
# checked out when the merge happens:
#
#   ifcmerge        — use when local (%A) is a working/PR branch and
#                     remote (%B) is main/master.  Default behaviour
#                     preserves remote (main) IDs.
#                     e.g. rebasing or updating a PR branch from main.
#
#   ifcmerge_ours   — use when local (%A) is main/master and remote (%B)
#                     is a working/PR branch.  --prioritise-local preserves
#                     local (main) IDs.
#                     e.g. Forgejo "Merge commit" button (standard PR merge).
#
# Use the "Merge commit" strategy in Forgejo (not rebase or squash) so that
# %A is always the base branch — ifcmerge_ours is then the correct driver.

[core]
    attributesFile = /etc/gitattributes

[merge "ifcmerge"]
    name = IFC merge driver (merging from main into working branch)
    driver = ifcmerge %O %A %B %A

[merge "ifcmerge_ours"]
    name = IFC merge driver (merging PR branch into main)
    driver = ifcmerge --prioritise-local %O %A %B %A