[git-users] Re: Problem with moving everything into a subdirectory; merge conflicts
Hi Philip, Am 2013-01-08 00:02, schrieb Philip Oakley: That is, do I understand correctly that if I had used the default merge strategy, and somehow solved all the conflicts (so that none of the files had been changed from F), the result would have technically been exactly the same? Obviously/hopefully your solution to any conflicts would have ended up being an ours choice anyway... Given that you already had a recent merge before the restructuring I would expect that it would be exactl;y the same! Ok, things seem to work very well: I'm not ready yet to test if *future* commits on the two branches, and future merges among them, will work as expected, but it looks as if everything worked out exactly as hoped. :-) Philip, thank you very much for your help! Best regards, Carsten -- Cafu - the open-source Game and Graphics Engine for multiplayer, cross-platform, real-time 3D Action Learn more at http://www.cafu.de --
[git-users] Re: Problem with moving everything into a subdirectory; merge conflicts
Hi Philip, Am 2013-01-06 18:21, schrieb Philip Oakley: Your issue [my mistake] is that the (gits's) merge process is a three way merge, so you have the two commits F and N to merge, but git will also locate the merge-base at M (which has the old directory structure), and compares the diffs between them [M-F] and [M-N] (AFAIKI), so you will get these hundreds (thousands) of renames on that basis, and a great difficulty in (git) trying to decide what to do. Thank you very much for that explanation, it helps me a lot with understanding this! So I'm thinking that it would be useful to have a merge commit, if possible, immediately before the two flag day change commits, and then adjust the level of rename detection (--rename-threshold) on the subsequent merge. (can't remember the default threshold) I had this (a helper merge commit), indeed not strictly immediately before the flag day change commit, but close enough so that I should have recognized if the affected files from the few intermediate commits (between the last merge commit and D) were involved in or responsible for the conflicts. However, it rather looked as if a main source of trouble were a large number of index.html sentinel files: As they all have the exact same contents, it seemed that the rename detection started to associate files at completely different, unrelated paths with each other. Also you could simply try an Ours/Theirs strategy (as appropriate) which would stop git trying to do more than it needs to, given that you will already have carefully made the two tree 'compatible' ;-) which will establish a new merge base for future merges. Ah!! :-) I really should have thought of trying this myself. Using git merge -s ours master worked quickly and without any problems, and created the new merge commit G just as expected. However, I'm unsure if this is the proper solution: Of course, logically I expected that commits F and G have the same tree (as G's only purpose is to serve as a new merge basis), even if G was created with the default merge strategy. The ours strategy does exactly that (refer to same tree in G) quasi on the direct route, per definition. But I wonder if this argument is enough? That is, do I understand correctly that if I had used the default merge strategy, and somehow solved all the conflicts (so that none of the files had been changed from F), the result would have technically been exactly the same? Best regards, Carsten -- Cafu - the open-source Game and Graphics Engine for multiplayer, cross-platform, real-time 3D Action Learn more at http://www.cafu.de --
Re: [git-users] Re: Problem with moving everything into a subdirectory; merge conflicts
From: Carsten Fuchs carsten.fu...@cafu.de Sent: Monday, January 07, 2013 9:21 AM Hi Philip, Am 2013-01-06 18:21, schrieb Philip Oakley: Your issue [my mistake] is that the (gits's) merge process is a three way merge, so you have the two commits F and N to merge, but git will also locate the merge-base at M (which has the old directory structure), and compares the diffs between them [M-F] and [M-N] (AFAIKI), so you will get these hundreds (thousands) of renames on that basis, and a great difficulty in (git) trying to decide what to do. Thank you very much for that explanation, it helps me a lot with understanding this! So I'm thinking that it would be useful to have a merge commit, if possible, immediately before the two flag day change commits, and then adjust the level of rename detection (--rename-threshold) on the subsequent merge. (can't remember the default threshold) I had this (a helper merge commit), indeed not strictly immediately before the flag day change commit, but close enough so that I should have recognized if the affected files from the few intermediate commits (between the last merge commit and D) were involved in or responsible for the conflicts. However, it rather looked as if a main source of trouble were a large number of index.html sentinel files: As they all have the exact same contents, it seemed that the rename detection started to associate files at completely different, unrelated paths with each other. They do sound like they would give some hassle to rename detection! Also you could simply try an Ours/Theirs strategy (as appropriate) which would stop git trying to do more than it needs to, given that you will already have carefully made the two tree 'compatible' ;-) which will establish a new merge base for future merges. Ah!! :-) I really should have thought of trying this myself. Using git merge -s ours master worked quickly and without any problems, and created the new merge commit G just as expected. However, I'm unsure if this is the proper solution: Of course, logically I expected that commits F and G have the same tree (as G's only purpose is to serve as a new merge basis), even if G was created with the default merge strategy. The ours strategy does exactly that (refer to same tree in G) quasi on the direct route, per definition. But I wonder if this argument is enough? There are two separate issues, one is to create a merge-base (any base) with the new layout (i.e. structure effects), and the second is to ensure you have the right (good-enough) basis (i.e. content) in your merge. Between the two you will then have easy rename detection and easy content merging. Normally structure variations are small, so the normal rename detection heuristic is OK, but in your case that promise wasn't kept. That is, do I understand correctly that if I had used the default merge strategy, and somehow solved all the conflicts (so that none of the files had been changed from F), the result would have technically been exactly the same? Obviously/hopefully your solution to any conflicts would have ended up being an ours choice anyway... Given that you already had a recent merge before the restructuring I would expect that it would be exactl;y the same! Best regards, Carsten --
Re: [git-users] Re: Problem with moving everything into a subdirectory; merge conflicts
Aha, I think I see it now... Your issue [my mistake] is that the (gits's) merge process is a three way merge, so you have the two commits F and N to merge, but git will also locate the merge-base at M (which has the old directory structure), and compares the diffs between them [M-F] and [M-N] (AFAIKI), so you will get these hundreds (thousands) of renames on that basis, and a great difficulty in (git) trying to decide what to do. So I'm thinking that it would be useful to have a merge commit, if possible, immediately before the two flag day change commits, and then adjust the level of rename detection (--rename-threshold) on the subsequent merge. (can't remember the default threshold) Also you could simply try an Ours/Theirs strategy (as appropriate) which would stop git trying to do more than it needs to, given that you will already have carefully made the two tree 'compatible' ;-) which will establish a new merge base for future merges. Philip - Original Message - From: Carsten Fuchs carsten.fu...@cafu.de To: public-git-users-/jypxa39uh5tlh3mboc...@plane.gmane.org Sent: Sunday, January 06, 2013 3:05 PM Subject: [git-users] Re: Problem with moving everything into a subdirectory; merge conflicts Hi Philip, Am 2013-01-06 14:59, schrieb Philip Oakley: Surley (?) the simplest method, given your limited number of branches, is to capture and repeat the moves as a script once for each branch, so that each branch has a flag day commit. Then the development merging should proceed just fine. At least then the file rename machinery has much less to worry about for any (real) conflicts that may happen. It will normally show the file renames just in case.. Thanks for your reply! Repeating the move commands for each branch and a flag day commit for each is what I tried already: see the second attempt in my original mail, commits F and N, which I tried to merge into G. I just tried this again in order to capture the full error messages it provides: Being on branch develop at commit F, running git merge master yields two types of error messages: CONFLICT (rename/delete): www/wiki/inc/lang/en/lang.php deleted in HEAD and renamed in master. Version master of www/wiki/inc/lang/en/lang.php left in tree. I believe this is for all those that I have modified in develop. However (as all I did was moving things into www/ ), I don't seem to understand what this message means, much less how to fix it. CONFLICT (rename/rename): Rename xmlrpc/includes/index.html-www/plugins/system/legacy/index.html in branch HEAD rename xmlrpc/includes/index.html-www/xmlrpc/includes/index.html in master And this occurs apparently for *every* other file (even though the mentioned file is 100% identical, same SHA-1, in both branches). In this case, I understand even less what the problem is and how to fix it. After about 2000 of these messages, the merge aborts with: warning: inexact rename detection was skipped due to too many files. warning: you may want to set your merge.renamelimit variable to at least 8288 and retry the command. Automatic merge failed; fix conflicts and then commit the result. So I did this: git config merge.renameLimit 3 git merge --abort git merge master but while the messages are slightly different now, the result is essentially the same, still hundreds of messages like: CONFLICT (rename/rename): Rename xmlrpc/includes/index.html-www/plugins/system/legacy/index.html in branch HEAD rename xmlrpc/includes/index.html-www/xmlrpc/includes/index.html in master CONFLICT (rename/delete): www/forum/images/smilies/icon_question.gif deleted in HEAD and renamed in master. Version master of www/forum/images/smilies/icon_question.gif left in tree. # [...], then after the last: Automatic merge failed; fix conflicts and then commit the result. So the question still stands... Best regards, Carsten - Original Message - From: Carsten Fuchs carsten.fuchs-sdyparl0...@public.gmane.org To: git-users-/jypxa39uh5tlh3mboc...@public.gmane.org Sent: Sunday, January 06, 2013 12:43 PM Subject: [git-users] Problem with moving everything into a subdirectory; merge conflicts [...] So I deleted E again (reset develop back to D), repeated the above move-and-commit commands at D in order to mimic things in the develop branch, obtaining F, and *then* tried to merge master into develop to obtain G: o---o---o---...---o---o---D ---F ---G -- develop / / / / o---o---o---o---...---M ---N ---ยด -- master To my surprise, this caused conflicts for quasi every of the affected 11000 files as well. Unfortunately I didn't keep a copy of the exact messages, but essentially the reported conflict was that the file has been renamed on one side, and has been renamed on the other side as well. What can we do? Best regards, Carsten -- Cafu - the open-source Game and Graphics Engine
