Patching in git is rather straightforward, though the commands are not all that obvious and the man pages are not terribly intuitive. Patching is used to move commits from one repository to another indirectly.
To create a patch, use git format-patch. It will spit out a series of patch files with one commit in each patch. Examples:
Only the newest commit:
git format-patch HEAD^
The last three commits:
git format-patch HEAD~3
The 4th through 2nd last commit:
git format-patch -3 HEAD~4
Only the commit deadbeef…
git format-patch -1 deadbeef
The last 10 commits, but without modifying the commit messages:
git format-patch -k HEAD~10
Patches do not always apply correctly. Before using git am to apply a patch, it is always a good idea to check it first with git apply.
To see what a patch will change, run:
git apply --stat 0001-mypatch.patch
To see how a patch will apply, run:
git apply --check 0001-mypatch.patch
If you're confident the patch will apply and isn't changing anything strange, then apply it with git am.
The easiest way to apply patches is with git am. To apply the patch 0001-mypatch.patch, run
git am 0001-mypatch.patch
To sign off patches as they are committed, use -s like so:
git am -s 0001-mypatch.patch
To fudge the commit date to be the same as the author date, use –committer-date-is-author-date like so::
git am --committer-date-is-author-date 0001-mypatch.patch