[PATCH 3/5] Documentation/rev-list-options.txt: Explain --ancestry-path
- From
Johan Herland <johan@herland.net>
- Date
- Jun 3, 2010, 23:17 UTC
- Message-ID
- <1275607057-26645-4-git-send-email-johan@herland.net>
- In-Reply-To
- <1275607057-26645-1-git-send-email-johan@herland.net>
Add a short paragraph explaining --ancestry-path, followed by a more detailed example. This mirrors how the other history simplification options are documented.
Signed-off-by: Johan Herland <johan@herland.net> --- Documentation/rev-list-options.txt | 50 ++++++++++++++++++++++++++++++++++- 1 files changed, 48 insertions(+), 2 deletions(-)
diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt index 81815e1..a33dd00 100644 --- a/Documentation/rev-list-options.txt +++ b/Documentation/rev-list-options.txt @@ -384,6 +384,14 @@ Default mode:: merges from the resulting history, as there are no selected commits contributing to this merge. +--ancestry-path:: + + When given a range of commits to display (e.g. 'commit1..commit2' + or 'commit2 {caret}commit1'), only display commits that exist + directly on the ancestry chain between the 'commit1' and + 'commit2', i.e. commits that are both descendants of 'commit1', + and ancestors of 'commit2'. + A more detailed explanation follows. Suppose you specified `foo` as the <paths>. We shall call commits @@ -511,8 +519,6 @@ Note that without '\--full-history', this still simplifies merges: if one of the parents is TREESAME, we follow only that one, so the other sides of the merge are never walked. -Finally, there is a fourth simplification mode available: - --simplify-merges:: First, build a history graph in the same way that @@ -554,6 +560,46 @@ Note the major differences in `N` and `P` over '\--full-history': removed completely, because it had one parent and is TREESAME. -- +Finally, there is a fifth simplification mode available: + +--ancestry-path:: + + Limit the displayed commits to those directly on the ancestry + chain between the "from" and "to" commits in the given commit + range. I.e. only display commits that are ancestor of the "to" + commit, and descendants of the "from" commit. ++ +As an example use case, consider the following commit history: ++ +----------------------------------------------------------------------- + D---E-------F + / \ \ + B---C---G---H---I---J + / \ + A-------K---------------L--M +----------------------------------------------------------------------- ++ +A regular 'D..M' computes the set of commits that are ancestors of `M`, +but excludes the ones that are ancestors of `D`. This is useful to see +what happened to the history leading to `M` since `D`, in the sense +that "what does `M` have that did not exist in `D`". The result in this +example would be all the commits, except `A` and `B` (and `D` itself, +of course). ++ +When we want to find out what commits in `M` are contaminated with the +bug introduced by `D` and need fixing, however, we might want to view +only the subset of 'D..M' that are actually descendants of `D`, i.e. +excluding `C` and `K`. This is exactly what the '\--ancestry-path' +option does. Applied to the 'D..M' range, it results in: ++ +----------------------------------------------------------------------- + E-------F + \ \ + G---H---I---J + \ + L--M +----------------------------------------------------------------------- + The '\--simplify-by-decoration' option allows you to view only the big picture of the topology of the history, by omitting commits that are not referenced by tags. Commits are marked as !TREESAME -- 1.7.0.4