[PATCH 0/3] contrib/subtree: process out-of-prefix subtrees

* cs/subtree-remove-optimization:
  Remove an optimization that can exclude too much
  history during a "subtree split."

Remove an optimization introduced in 98ba49ccc2 (subtree: fix split processing with multiple subtrees present, 2023-12-01). The optimization incorrectly excludes commits from the split history that must be included.

The above commit, and my later attempt to fix it in 83f9dad7d6 (contrib/subtree: fix split with squashed subtrees, 2025-09-09), both introduce known regressions.

Improve test coverage for `copy_or_skip`, which will help detect future regressions.

Colin Stagner (3):
  contrib/subtree: capture additional test-cases
  contrib/subtree: test history depth
  contrib/subtree: process out-of-prefix subtrees

 contrib/subtree/git-subtree.sh     |  50 +-------
 contrib/subtree/t/t7900-subtree.sh | 198 +++++++++++++++++++++++++++--
 2 files changed, 190 insertions(+), 58 deletions(-)

base-commit: 852829b3dd2fe4e7c7fc4d8badde644cf1b66c74