On Sat, Apr 20, 2024 at 11:00:45AM +0800, wuzhouhui14 wrote: > Suppose I have two branches with following commit histories: > > B----C---D(directory abc/ modified) Branch1 > / > L--M---O(directory abc/ not modified) Branch2 > > In previous graph, the Branch1 merge Branch2 in commit C. After commit C, > the Branch1 modified some contents in director abc/. Branch2 doesn't > modify directory abc/ since commit M, which has been merged into Branch1. > > Then, when I do: > > git checkout Branch1 > git merge Branch2 > > the director abc/ contains conflicts, why? Because the director abc/ doesn't > changed since commit M in Branch2, so directory abc/ should not have > conflicts. There should not be any conflict (and FWIW I've just verified there is not using a simple test repository). I can suggest three reasons (while probably there could be more): - The contents of abc has been changed in M; in other words, abc as recorded in M is different from its state in C. - The files in abc as recorded in D and O have difference in line endings - such as on one branch they have LFs and on the other - CRLFs. - The graph in a real repository you're dealing with is more complicated than presented in your picture, and there exist commits between M and O - and may be between C and D as well - which have changed the state of abc, but you just failed to spot these modifications during your analysis. Here's a graph from my sample repository where I tried to model your situation: -------------------------------- 8< -------------------------------- $ git log --graph * commit 7fc08ef95934a404021b46f46df3250340b5122f |\ Merge: 2a72a51 2c8ef4f | | Author: user <user@xxxxxxxx> | | Date: Tue Apr 23 10:14:31 2024 +0300 | | | | Merge branch 'branch1' into branch2 | | | * commit 2c8ef4f49bf2a9900c009a04943422a66b2987c6 - on branch1 | | Author: user <user@xxxxxxxx> | | Date: Tue Apr 23 10:14:16 2024 +0300 | | | | modify bar.txt | | | * commit 001a394ef8d31785362241ef63ca422dad496b39 - M in your case | |\ Merge: b072e1e e8af26d | | | Author: user <user@xxxxxxxx> | | | Date: Tue Apr 23 10:13:11 2024 +0300 | | | | | | Merge branch 'branch2' into branch1 | | | | * | commit b072e1e86f7db47286bc08a435c71486c0ca4f77 - on branch 1 | | | Author: user <user@xxxxxxxx> | | | Date: Tue Apr 23 10:12:58 2024 +0300 | | | | | | add bar.txt | | | * | | commit 2a72a51b2aea87f6ed13013865eb181551eba31f - on branch2, like C | |/ Author: user <user@xxxxxxxx> |/| Date: Tue Apr 23 10:13:47 2024 +0300 | | | | modify abc/foo.txt again | | * | commit e8af26def1078e0293c46a22db3ad788fd6f38be - on branch2 | | Author: user <user@xxxxxxxx> | | Date: Tue Apr 23 10:12:08 2024 +0300 | | | | modify abc/foo.txt | | * | commit c7c0b344e943c9d548447886a50fa618e0c7f107 - branch2 is born |/ Author: user <user@xxxxxxxx> | Date: Tue Apr 23 10:11:42 2024 +0300 | | add abc/foo.txt | * commit 192905a78af1645603f54751ae7139d1aca22a80 Author: user <user@xxxxxxxx> Date: Tue Apr 23 10:10:56 2024 +0300 root commit -------------------------------- 8< --------------------------------