NAME
----
-git-patch-id - Some git command not yet documented.
-
+git-patch-id - Compute unique ID for a patch
SYNOPSIS
--------
-'git-patch-id' [ --option ] <args>...
+[verse]
+'git patch-id' < <patch>
DESCRIPTION
-----------
-Does something not yet documented.
+A "patch ID" is nothing but a SHA-1 of the diff associated with a patch, with
+whitespace and line numbers ignored. As such, it's "reasonably stable", but at
+the same time also reasonably unique, i.e., two patches that have the same "patch
+ID" are almost guaranteed to be the same thing.
+
+IOW, you can use this thing to look for likely duplicate commits.
+When dealing with 'git diff-tree' output, it takes advantage of
+the fact that the patch is prefixed with the object name of the
+commit, and outputs two 40-byte hexadecimal strings. The first
+string is the patch ID, and the second string is the commit ID.
+This can be used to make a mapping from patch ID to commit ID.
OPTIONS
-------
---option::
- Some option not yet documented.
-
-<args>...::
- Some argument not yet documented.
-
-
-Author
-------
-Written by Linus Torvalds <torvalds@osdl.org>
-
-Documentation
---------------
-Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
+<patch>::
+ The diff to create the ID of.
GIT
---
-Part of the link:git.html[git] suite
-
+Part of the linkgit:git[1] suite