nsect(NAME)

PATCHES - track and distribute your code changes

nsect(DESCRIPTION)

This page documents how to distribute your changes to GNU lilypond
(or in fact any other StepMake package).

nsect(ABSTRACT)

Distributing a change normally goes like this:

itemize(
it()make your fix/add your code 
it()Add changes to NEWS, and add yourself to Documentation/AUTHORS.yo
it()generate a patch, 
it()e-mail your patch to one of the mailing lists
    gnu-music-discuss@gnu.org or bug-gnu-music@gnu.org
)

nsect(GENERATING A PATCH)

In file(VERSION), set MY_PATCH_LEVEL:

verb(
    VERSION:
	...
	MY_PATCH_LEVEL=jcn1
)

In file(NEWS), enter a summary of changes:

verb(
    NEWS:
	pl 0.1.73.jcn1
		- added PATCHES.yo
)

Then, from the top of Lily's source tree, type

verb(
    make diff
)

which leaves your patch as file(./lilypond-0.1.73.jcn1.diff).

If you didn't configure Lily using --srcdir, you can do:

verb(
    make release

    tar-ball: ../patches/lilypond-0.1.73.jcn1.gz
    patch: ../patches/lilypond-0.1.73.jcn1.gz
    updeet: ../test/updeet
)

nsect(PREREQUISITES)

For creating a patch you need

itemize(
it()All items mentioned in file(INSTALL).  You're not going to send a patch
    that you haven't even built, right?
it()GNU diff
it()Python (version 1.5 or newer).  
    You can of course make a patch by hand, which would go something like:

verb(
    make distclean
    cd ..
    diff -urN lilypond-0.1.73 lilypond-0.1.73.jcn1 > lilypond-0.1.73.jcn1
)

but there are handy python scripts available.  If you're doing development,
you'll need Python for other LilyPond scripts anyway.

it()The Lily directory structure, which looks like:

includefile(../../stepmake/Documentation/layout.yo)
)
	
nsect(APPLYING PATCHES)

If you're following LilyPond development regularly, you probably want to
download just the patch for each subsequent release.
After downloading the patch (into the patches directory, of course), simply 
apply it:

verb(
    gzip -dc ../patches/lilypond-0.1.74.diff.gz | patch -p1 -E
)

and don't forget to make automatically generated files:

verb(
    autoconf footnote(patches don't include automatically generated files, 
    i.e. file(configure) and files generated by file(configure).)

    configure
)

nsect(SYNCHRONISE)

If you're not very quick with sending your patch, there's a good chance
that an new release of LilyPond comes available.  In such a case (and
sometimes for other unkown reasons :-), the maintainer will probably ask
you to make a new patch against the latest release.
Your best bet is to download the latest release, and apply your patch
against this new source tree:

verb(
    cd lilypond-0.1.74
    gzip -dc ../patches/lilypond-0.1.73.jcn1.diff.gz | patch -p1 -E
    autoconf
    configure
)

Then, make a patch as shown above.

nsect(SEE ALSO)

file(stepmake/INSTALL.txt)

nsect(MAINTAINER)

nemail(Han-Wen Nienhuys)(hanwen@cs.uu.nl)

Just keep on sending those patches!