+DISCUSSION
+----------
+
+The tables below show what happens when running:
+
+----------
+git reset --option target
+----------
+
+to reset the HEAD to another commit (`target`) with the different
+reset options depending on the state of the files.
+
+In these tables, A, B, C and D are some different states of a
+file. For example, the first line of the first table means that if a
+file is in state A in the working tree, in state B in the index, in
+state C in HEAD and in state D in the target, then "git reset --soft
+target" will put the file in state A in the working tree, in state B
+in the index and in state D in HEAD.
+
+ working index HEAD target working index HEAD
+ ----------------------------------------------------
+ A B C D --soft A B D
+ --mixed A D D
+ --hard D D D
+ --merge (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
+
+"reset --merge" is meant to be used when resetting out of a conflicted
+merge. Any mergy operation guarantees that the work tree file that is
+involved in the merge does not have local change wrt the index before
+it starts, and that it writes the result out to the work tree. So if
+we see some difference between the index and the target and also
+between the index and the work 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.
+
+"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.
+
projects / git.git / blobdiff