<commit>::
Commit to make the current HEAD. If not given defaults to HEAD.
+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.
+
+ 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)
+
+ 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)
+
+ 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
+
+ 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
+
+In these tables, A, B, C and D are some different states of a
+file. For example, the last line of the last table means that if a
+file is in state B in the working tree and the index, and in a
+different state C in HEAD and in the target, then "git reset
+--merge target" will put the file in state C in the working tree,
+in the index and in HEAD.
+
+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
+
+ 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
+
+X means any state and U means an unmerged index.
+
Examples
--------
$ git reset --hard <2>
$ git pull . topic/branch <3>
Updating from 41223... to 13134...
-Fast forward
+Fast-forward
$ git reset --hard ORIG_HEAD <4>
------------
+
which is a synonym for "git reset --hard HEAD" clears the mess
from the index file and the working tree.
<3> Merge a topic branch into the current branch, which resulted
-in a fast forward.
+in a fast-forward.
<4> But you decided that the topic branch is not ready for public
consumption yet. "pull" or "merge" always leaves the original
tip of the current branch in ORIG_HEAD, so resetting hard to it