^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) .. _modifyingpatches:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) Modifying Patches
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) =================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) If you are a subsystem or branch maintainer, sometimes you need to slightly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) modify patches you receive in order to merge them, because the code is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) exactly the same in your tree and the submitters'. If you stick strictly to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) rule (c) of the developers certificate of origin, you should ask the submitter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) to rediff, but this is a totally counter-productive waste of time and energy.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) Rule (b) allows you to adjust the code, but then it is very impolite to change
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) one submitters code and make him endorse your bugs. To solve this problem, it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) is recommended that you add a line between the last Signed-off-by header and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) yours, indicating the nature of your changes. While there is nothing mandatory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) about this, it seems like prepending the description with your mail and/or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) name, all enclosed in square brackets, is noticeable enough to make it obvious
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) that you are responsible for last-minute changes. Example::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) Signed-off-by: Random J Developer <random@developer.example.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) [lucky@maintainer.example.org: struct foo moved from foo.c to foo.h]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) Signed-off-by: Lucky K Maintainer <lucky@maintainer.example.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) This practice is particularly helpful if you maintain a stable branch and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) want at the same time to credit the author, track changes, merge the fix,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) and protect the submitter from complaints. Note that under no circumstances
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) can you change the author's identity (the From header), as it is the one
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) which appears in the changelog.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) Special note to back-porters: It seems to be a common and useful practice
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) to insert an indication of the origin of a patch at the top of the commit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) message (just after the subject line) to facilitate tracking. For instance,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) here's what we see in a 3.x-stable release::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) Date: Tue Oct 7 07:26:38 2014 -0400
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) libata: Un-break ATA blacklist
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) commit 1c40279960bcd7d52dbdf1d466b20d24b99176c8 upstream.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) And here's what might appear in an older kernel once a patch is backported::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) Date: Tue May 13 22:12:27 2008 +0200
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) wireless, airo: waitbusy() won't delay
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) [backport of 2.6 commit b7acbdfbd1f277c1eb23f344f899cfa4cd0bf36a]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) Whatever the format, this information provides a valuable help to people
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) tracking your trees, and to people trying to troubleshoot bugs in your
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) tree.