diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/RelNotes-1.6.1.txt | 19 | ||||
| -rw-r--r-- | Documentation/config.txt | 8 | ||||
| -rw-r--r-- | Documentation/git-fsck.txt | 3 | ||||
| -rw-r--r-- | Documentation/git-revert.txt | 8 | ||||
| -rw-r--r-- | Documentation/git-show-branch.txt | 2 | ||||
| -rw-r--r-- | Documentation/howto/revert-a-faulty-merge.txt | 179 |
6 files changed, 212 insertions, 7 deletions
diff --git a/Documentation/RelNotes-1.6.1.txt b/Documentation/RelNotes-1.6.1.txt index 0405309743..002d9ec681 100644 --- a/Documentation/RelNotes-1.6.1.txt +++ b/Documentation/RelNotes-1.6.1.txt @@ -230,6 +230,13 @@ Fixes since v1.6.0 All of the fixes in v1.6.0.X maintenance series are included in this release, unless otherwise noted. +* Porcelains implemented as shell scripts were utterly confused when you + entered to a subdirectory of a work tree from sideways, following a + symbolic link (this may need to be backported to older releases later). + +* Tracking symbolic links would work better on filesystems whose lstat() + returns incorrect st_size value for them. + * "git add" and "git update-index" incorrectly allowed adding S/F when S is a tracked symlink that points at a directory D that has a path F in it (we still need to fix a similar nonsense when S is a submodule and F @@ -244,6 +251,16 @@ release, unless otherwise noted. * "git filter-branch" failed to rewrite a tag name with slashes in it. +* "git http-push" did not understand URI scheme other than opaquelocktoken + when acquiring a lock from the server (this may need to be backported to + older releases later). + +* "git revert" records relative to which parent a revert was made when + reverting a merge. Together with new documentation that explains issues + around reverting a merge and merging from the updated branch later, this + hopefully will reduce user confusion (this may need to be backported to + older releases later). + * "git rm --cached" used to allow an empty blob that was added earlier to be removed without --force, even when the file in the work tree has since been modified. @@ -260,6 +277,6 @@ release, unless otherwise noted. -- exec >/var/tmp/1 -O=v1.6.1-rc1-55-gd8af75d +O=v1.6.1-rc3-74-gf66bc5f echo O=$(git describe master) git shortlog --no-merges $O..master ^maint diff --git a/Documentation/config.txt b/Documentation/config.txt index 21ea16590b..52786c7df5 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -601,10 +601,6 @@ diff.autorefreshindex:: affects only 'git-diff' Porcelain, and not lower level 'diff' commands, such as 'git-diff-files'. -diff.suppress-blank-empty:: - A boolean to inhibit the standard behavior of printing a space - before each empty output line. Defaults to false. - diff.external:: If this config variable is set, diff generation is not performed using the internal diff machinery, but using the @@ -639,6 +635,10 @@ diff.renames:: will enable basic rename detection. If set to "copies" or "copy", it will detect copies, as well. +diff.suppress-blank-empty:: + A boolean to inhibit the standard behavior of printing a space + before each empty output line. Defaults to false. + fetch.unpackLimit:: If the number of objects fetched over the git native transfer is below this diff --git a/Documentation/git-fsck.txt b/Documentation/git-fsck.txt index d5a7647219..287c4fc5e0 100644 --- a/Documentation/git-fsck.txt +++ b/Documentation/git-fsck.txt @@ -79,7 +79,8 @@ that aren't readable from any of the specified head nodes. So for example - git fsck --unreachable HEAD $(cat .git/refs/heads/*) + git fsck --unreachable HEAD \ + $(git for-each-ref --format="%(objectname)" refs/heads) will do quite a _lot_ of verification on the tree. There are a few extra validity tests to be added (make sure that tree objects are diff --git a/Documentation/git-revert.txt b/Documentation/git-revert.txt index caa07298a6..5e1175800a 100644 --- a/Documentation/git-revert.txt +++ b/Documentation/git-revert.txt @@ -44,6 +44,14 @@ OPTIONS option specifies the parent number (starting from 1) of the mainline and allows revert to reverse the change relative to the specified parent. ++ +Reverting a merge commit declares that you will never want the tree changes +brought in by the merge. As a result, later merges will only bring in tree +changes introduced by commits that are not ancestors of the previously +reverted merge. This may or may not be what you want. ++ +See the link:howto/revert-a-faulty-merge.txt[revert-a-faulty-merge How-To] for +more details. --no-edit:: With this option, 'git-revert' will not start the commit diff --git a/Documentation/git-show-branch.txt b/Documentation/git-show-branch.txt index fb269fff87..8277577a6f 100644 --- a/Documentation/git-show-branch.txt +++ b/Documentation/git-show-branch.txt @@ -172,7 +172,7 @@ only the primary branches. In addition, if you happen to be on your topic branch, it is shown as well. ------------ -$ git show-branch --reflog='10,1 hour ago' --list master +$ git show-branch --reflog="10,1 hour ago" --list master ------------ shows 10 reflog entries going back from the tip as of 1 hour ago. diff --git a/Documentation/howto/revert-a-faulty-merge.txt b/Documentation/howto/revert-a-faulty-merge.txt new file mode 100644 index 0000000000..39b1da440a --- /dev/null +++ b/Documentation/howto/revert-a-faulty-merge.txt @@ -0,0 +1,179 @@ +Date: Fri, 19 Dec 2008 00:45:19 -0800 +From: Linus Torvalds <torvalds@linux-foundation.org>, Junio C Hamano <gitster@pobox.com> +Subject: Re: Odd merge behaviour involving reverts +Abstract: Sometimes a branch that was already merged to the mainline + is later found to be faulty. Linus and Junio give guidance on + recovering from such a premature merge and continuing development + after the offending branch is fixed. +Message-ID: <7vocz8a6zk.fsf@gitster.siamese.dyndns.org> +References: <alpine.LFD.2.00.0812181949450.14014@localhost.localdomain> + +Alan <alan@clueserver.org> said: + + I have a master branch. We have a branch off of that that some + developers are doing work on. They claim it is ready. We merge it + into the master branch. It breaks something so we revert the merge. + They make changes to the code. they get it to a point where they say + it is ok and we merge again. + + When examined, we find that code changes made before the revert are + not in the master branch, but code changes after are in the master + branch. + +and asked for help recovering from this situation. + +The history immediately after the "revert of the merge" would look like +this: + + ---o---o---o---M---x---x---W + / + ---A---B + +where A and B are on the side development that was not so good, M is the +merge that brings these premature changes into the mainline, x are changes +unrelated to what the side branch did and already made on the mainline, +and W is the "revert of the merge M" (doesn't W look M upside down?). +IOW, "diff W^..W" is similar to "diff -R M^..M". + +Such a "revert" of a merge can be made with: + + $ git revert -m 1 M + +After the develpers of the side branch fixes their mistakes, the history +may look like this: + + ---o---o---o---M---x---x---W---x + / + ---A---B-------------------C---D + +where C and D are to fix what was broken in A and B, and you may already +have some other changes on the mainline after W. + +If you merge the updated side branch (with D at its tip), none of the +changes made in A nor B will be in the result, because they were reverted +by W. That is what Alan saw. + +Linus explains the situation: + + Reverting a regular commit just effectively undoes what that commit + did, and is fairly straightforward. But reverting a merge commit also + undoes the _data_ that the commit changed, but it does absolutely + nothing to the effects on _history_ that the merge had. + + So the merge will still exist, and it will still be seen as joining + the two branches together, and future merges will see that merge as + the last shared state - and the revert that reverted the merge brought + in will not affect that at all. + + So a "revert" undoes the data changes, but it's very much _not_ an + "undo" in the sense that it doesn't undo the effects of a commit on + the repository history. + + So if you think of "revert" as "undo", then you're going to always + miss this part of reverts. Yes, it undoes the data, but no, it doesn't + undo history. + +In such a situation, you would want to first revert the previous revert, +which would make the history look like this: + + ---o---o---o---M---x---x---W---x---Y + / + ---A---B-------------------C---D + +where Y is the revert of W. Such a "revert of the revert" can be done +with: + + $ git revert W + +This history would (ignoring possible conflicts between what W and W..Y +changed) be equivalent to not having W nor Y at all in the history: + + ---o---o---o---M---x---x-------x---- + / + ---A---B-------------------C---D + +and merging the side branch again will not have conflict arising from an +earlier revert and revert of the revert. + + ---o---o---o---M---x---x-------x-------* + / / + ---A---B-------------------C---D + +Of course the changes made in C and D still can conflict with what was +done by any of the x, but that is just a normal merge conflict. + +On the other hand, if the developers of the side branch discarded their +faulty A and B, and redone the changes on top of the updated mainline +after the revert, the history would have looked like this: + + ---o---o---o---M---x---x---W---x---x + / \ + ---A---B A'--B'--C' + +If you reverted the revert in such a case as in the previous example: + + ---o---o---o---M---x---x---W---x---x---Y---* + / \ / + ---A---B A'--B'--C' + +where Y is the revert of W, A' and B'are rerolled A and B, and there may +also be a further fix-up C' on the side branch. "diff Y^..Y" is similar +to "diff -R W^..W" (which in turn means it is similar to "diff M^..M"), +and "diff A'^..C'" by definition would be similar but different from that, +because it is a rerolled series of the earlier change. There will be a +lot of overlapping changes that result in conflicts. So do not do "revert +of revert" blindly without thinking.. + + ---o---o---o---M---x---x---W---x---x + / \ + ---A---B A'--B'--C' + +In the history with rebased side branch, W (and M) are behind the merge +base of the updated branch and the tip of the mainline, and they should +merge without the past faulty merge and its revert getting in the way. + +To recap, these are two very different scenarios, and they want two very +different resolution strategies: + + - If the faulty side branch was fixed by adding corrections on top, then + doing a revert of the previous revert would be the right thing to do. + + - If the faulty side branch whose effects were discarded by an earlier + 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. + +However, there are things to keep in mind when reverting a merge (and +reverting such a revert). + +For example, think about what reverting a merge (and then reverting the +revert) does to bisectability. Ignore the fact that the revert of a revert +is undoing it - just think of it as a "single commit that does a lot". +Because that is what it does. + +When you have a problem you are chasing down, and you hit a "revert this +merge", what you're hitting is essentially a single commit that contains +all the changes (but obviously in reverse) of all the commits that got +merged. So it's debugging hell, because now you don't have lots of small +changes that you can try to pinpoint which _part_ of it changes. + +But does it all work? Sure it does. You can revert a merge, and from a +purely technical angle, git did it very naturally and had no real +troubles. It just considered it a change from "state before merge" to +"state after merge", and that was it. Nothing complicated, nothing odd, +nothing really dangerous. Git will do it without even thinking about it. + +So from a technical angle, there's nothing wrong with reverting a merge, +but from a workflow angle it's something that you generally should try to +avoid. + +If at all possible, for example, if you find a problem that got merged +into the main tree, rather than revert the merge, try _really_ hard to +bisect the problem down into the branch you merged, and just fix it, or +try to revert the individual commit that caused it. + +Yes, it's more complex, and no, it's not always going to work (sometimes +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. |