why git commit --amend make confliction happened? that is quite strange

Question

*   84b134d - (HEAD, origin/lab_master, lab_master) comment macro defination which is protent to be a fun
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| * 735d88f - add small script to ease ctag related option (13 minutes ago) 
* | 6623a94 - add small script to ease ctag related option (4 minutes ago) 
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* 0d0913a - add gitignore to ignore ctags file (57 minutes ago) 

735d88f is a --amend commit, but conflict happened at this moment, why?

i have only one pc, and i always edit files on it, also i have only one local repo, what's more this repo is only used by here, i think there is no possibility that conflict may happen?

but it happened, why?

Answer 1

It is best to amend only commits you have not already pushed to your server. Once you push a commit, if you try to amend it and push it, it will result in a conflict because you have changed history (as recorded on the server).