diff options
Diffstat (limited to 'Documentation/howto')
| -rw-r--r-- | Documentation/howto/maintain-git.txt | 15 | ||||
| -rw-r--r-- | Documentation/howto/revert-a-faulty-merge.txt | 90 | ||||
| -rw-r--r-- | Documentation/howto/revert-branch-rebase.txt | 10 | ||||
| -rw-r--r-- | Documentation/howto/update-hook-example.txt | 2 | ||||
| -rw-r--r-- | Documentation/howto/using-merge-subtree.txt | 2 |
5 files changed, 101 insertions, 18 deletions
diff --git a/Documentation/howto/maintain-git.txt b/Documentation/howto/maintain-git.txt index 4357e26913..8823a37067 100644 --- a/Documentation/howto/maintain-git.txt +++ b/Documentation/howto/maintain-git.txt @@ -59,7 +59,7 @@ The policy. not yet pass the criteria set for 'next'. - The tips of 'master', 'maint' and 'next' branches will always - fast forward, to allow people to build their own + fast-forward, to allow people to build their own customization on top of them. - Usually 'master' contains all of 'maint', 'next' contains all @@ -176,7 +176,7 @@ by doing the following: - Update "What's cooking" message to review the updates to existing topics, newly added topics and graduated topics. - This step is helped with Meta/UWC script (where Meta/ contains + This step is helped with Meta/cook script (where Meta/ contains a checkout of the 'todo' branch). - Merge topics to 'next'. For each branch whose tip is not @@ -197,10 +197,9 @@ by doing the following: - Nothing is next-worthy; do not do anything. - - Rebase topics that do not have any commit in next yet. This - step is optional but sometimes is worth doing when an old - series that is not in next can take advantage of low-level - framework change that is merged to 'master' already. + - [** OBSOLETE **] Optionally rebase topics that do not have any commit + in next yet, when they can take advantage of low-level framework + change that is merged to 'master' already. $ git rebase master ai/topic @@ -209,7 +208,7 @@ by doing the following: pre-rebase hook to make sure that topics that are already in 'next' are not rebased beyond the merged commit. - - Rebuild "pu" to merge the tips of topics not in 'next'. + - [** OBSOLETE **] Rebuild "pu" to merge the tips of topics not in 'next'. $ git checkout pu $ git reset --hard next @@ -241,7 +240,7 @@ by doing the following: - Fetch html and man branches back from k.org, and push four integration branches and the two documentation branches to - repo.or.cz + repo.or.cz and other mirrors. Some observations to be made. diff --git a/Documentation/howto/revert-a-faulty-merge.txt b/Documentation/howto/revert-a-faulty-merge.txt index 3b4a390005..6fd711996a 100644 --- a/Documentation/howto/revert-a-faulty-merge.txt +++ b/Documentation/howto/revert-a-faulty-merge.txt @@ -142,6 +142,8 @@ different resolution strategies: revert of a merge was rebuilt from scratch (i.e. rebasing and fixing, as you seem to have interpreted), then re-merging the result without doing anything else fancy would be the right thing to do. + (See the ADDENDUM below for how to rebuild a branch from scratch + without changing its original branching-off point.) However, there are things to keep in mind when reverting a merge (and reverting such a revert). @@ -177,3 +179,91 @@ the answer is: "oops, I really shouldn't have merged it, because it wasn't ready yet, and I really need to undo _all_ of the merge"). So then you really should revert the merge, but when you want to re-do the merge, you now need to do it by reverting the revert. + +ADDENDUM + +Sometimes you have to rewrite one of a topic branch's commits *and* you can't +change the topic's branching-off point. Consider the following situation: + + P---o---o---M---x---x---W---x + \ / + A---B---C + +where commit W reverted commit M because it turned out that commit B was wrong +and needs to be rewritten, but you need the rewritten topic to still branch +from commit P (perhaps P is a branching-off point for yet another branch, and +you want be able to merge the topic into both branches). + +The natural thing to do in this case is to checkout the A-B-C branch and use +"rebase -i P" to change commit B. However this does not rewrite commit A, +because "rebase -i" by default fast-forwards over any initial commits selected +with the "pick" command. So you end up with this: + + P---o---o---M---x---x---W---x + \ / + A---B---C <-- old branch + \ + B'---C' <-- naively rewritten branch + +To merge A-B'-C' into the mainline branch you would still have to first revert +commit W in order to pick up the changes in A, but then it's likely that the +changes in B' will conflict with the original B changes re-introduced by the +reversion of W. + +However, you can avoid these problems if you recreate the entire branch, +including commit A: + + A'---B'---C' <-- completely rewritten branch + / + P---o---o---M---x---x---W---x + \ / + A---B---C + +You can merge A'-B'-C' into the mainline branch without worrying about first +reverting W. Mainline's history would look like this: + + A'---B'---C'------------------ + / \ + P---o---o---M---x---x---W---x---M2 + \ / + A---B---C + +But if you don't actually need to change commit A, then you need some way to +recreate it as a new commit with the same changes in it. The rebase command's +--no-ff option provides a way to do this: + + $ git rebase [-i] --no-ff P + +The --no-ff option creates a new branch A'-B'-C' with all-new commits (all the +SHA IDs will be different) even if in the interactive case you only actually +modify commit B. You can then merge this new branch directly into the mainline +branch and be sure you'll get all of the branch's changes. + +You can also use --no-ff in cases where you just add extra commits to the topic +to fix it up. Let's revisit the situation discussed at the start of this howto: + + P---o---o---M---x---x---W---x + \ / + A---B---C----------------D---E <-- fixed-up topic branch + +At this point, you can use --no-ff to recreate the topic branch: + + $ git checkout E + $ git rebase --no-ff P + +yielding + + A'---B'---C'------------D'---E' <-- recreated topic branch + / + P---o---o---M---x---x---W---x + \ / + A---B---C----------------D---E + +You can merge the recreated branch into the mainline without reverting commit W, +and mainline's history will look like this: + + A'---B'---C'------------D'---E' + / \ + P---o---o---M---x---x---W---x---M2 + \ / + A---B---C diff --git a/Documentation/howto/revert-branch-rebase.txt b/Documentation/howto/revert-branch-rebase.txt index e70d8a31e7..093c656048 100644 --- a/Documentation/howto/revert-branch-rebase.txt +++ b/Documentation/howto/revert-branch-rebase.txt @@ -85,7 +85,7 @@ Fortunately I did not have to; what I have in the current branch ------------------------------------------------ $ git checkout master -$ git merge revert-c99 ;# this should be a fast forward +$ git merge revert-c99 ;# this should be a fast-forward Updating from 10d781b9caa4f71495c7b34963bef137216f86a8 to e3a693c... cache.h | 8 ++++---- commit.c | 2 +- @@ -95,7 +95,7 @@ Updating from 10d781b9caa4f71495c7b34963bef137216f86a8 to e3a693c... 5 files changed, 8 insertions(+), 8 deletions(-) ------------------------------------------------ -There is no need to redo the test at this point. We fast forwarded +There is no need to redo the test at this point. We fast-forwarded and we know 'master' matches 'revert-c99' exactly. In fact: ------------------------------------------------ @@ -112,25 +112,19 @@ $ git tag pu-anchor pu $ git rebase master * Applying: Redo "revert" using three-way merge machinery. First trying simple merge strategy to cherry-pick. -Finished one cherry-pick. * Applying: Remove git-apply-patch-script. First trying simple merge strategy to cherry-pick. Simple cherry-pick fails; trying Automatic cherry-pick. Removing Documentation/git-apply-patch-script.txt Removing git-apply-patch-script -Finished one cherry-pick. * Applying: Document "git cherry-pick" and "git revert" First trying simple merge strategy to cherry-pick. -Finished one cherry-pick. * Applying: mailinfo and applymbox updates First trying simple merge strategy to cherry-pick. -Finished one cherry-pick. * Applying: Show commits in topo order and name all commits. First trying simple merge strategy to cherry-pick. -Finished one cherry-pick. * Applying: More documentation updates. First trying simple merge strategy to cherry-pick. -Finished one cherry-pick. ------------------------------------------------ The temporary tag 'pu-anchor' is me just being careful, in case 'git diff --git a/Documentation/howto/update-hook-example.txt b/Documentation/howto/update-hook-example.txt index 697d918885..b7f8d416d6 100644 --- a/Documentation/howto/update-hook-example.txt +++ b/Documentation/howto/update-hook-example.txt @@ -76,7 +76,7 @@ case "$1" in if expr "$2" : '0*$' >/dev/null; then info "The branch '$1' is new..." else - # updating -- make sure it is a fast forward + # updating -- make sure it is a fast-forward mb=$(git-merge-base "$2" "$3") case "$mb,$2" in "$2,$mb") info "Update is fast-forward" ;; diff --git a/Documentation/howto/using-merge-subtree.txt b/Documentation/howto/using-merge-subtree.txt index 0953a50b69..2933056120 100644 --- a/Documentation/howto/using-merge-subtree.txt +++ b/Documentation/howto/using-merge-subtree.txt @@ -71,5 +71,5 @@ Additional tips relevant parts of your tree. - Please note that if the other project merges from you, then it will - connects its history to yours, which can be something they don't want + connect its history to yours, which can be something they don't want to. |