Git Reset Options with Unmerged Entries and Merge Conflicts

(disallowed) --keep (disallowed) .... .... working index HEAD target working index HEAD ---------------------------------------------------- A B C C --soft A B C --mixed A C C --hard C C C --merge (disallowed) --keep A C C .... .... working index HEAD target working index HEAD ---------------------------------------------------- B B C D --soft B B D --mixed B D D --hard D D D --merge D D D --keep (disallowed) .... .... working index HEAD target working index HEAD ---------------------------------------------------- B B C C --soft B B C --mixed B C C --hard C C C --merge C C C --keep B C C .... .... working index HEAD target working index HEAD ---------------------------------------------------- B C C D --soft B C D --mixed B D D --hard D D D --merge (disallowed) --keep (disallowed) .... .... working index HEAD target working index HEAD ---------------------------------------------------- B C C C --soft B C C --mixed B C C --hard C C C --merge B C C --keep B C C .... `git reset --merge` is meant to be used when resetting out of a conflicted merge. Any mergy operation guarantees that the working tree file that is involved in the merge does not have a local change with respect to the index before it starts, and that it writes the result out to the working tree. So if we see some difference between the index and the target and also between the index and the working tree, then it means that we are not resetting out from a state that a mergy operation left after failing with a conflict. That is why we disallow `--merge` option in this case. `git reset --keep` is meant to be used when removing some of the last commits in the current branch while keeping changes in the working tree. If there could be conflicts between the changes in the commit we want to remove and the changes in the working tree we want to keep, the reset is disallowed. That's why it is disallowed if there are both changes between the working tree and `HEAD`, and between `HEAD` and the target. To be safe, it is also disallowed when there are unmerged entries. The following tables show what happens when there are unmerged entries: .... working index HEAD target working index HEAD ---------------------------------------------------- X U A B --soft (disallowed) --mixed X B B --hard B B B --merge B B B --keep (disallowed) .... .... working index HEAD target working index HEAD ---------------------------------------------------- X U A A --soft (disallowed) --mixed X A A --hard A A A --merge A A A --keep (disallowed) .... `X` means any state and `U` means an unmerged index. GIT --- Part of the linkgit:git[1] suite

The text explains how `git reset` options (`--soft`, `--mixed`, `--hard`, `--merge`, and `--keep`) behave when there are unmerged entries or merge conflicts, providing tables to illustrate the outcomes for different file states and reset options, and outlines the rules for disallowing certain options in specific scenarios to prevent unintended changes or conflicts.