NAME

       dpkg-mergechangelogs - 3-way merge of debian/changelog files

SYNOPSIS

       dpkg-mergechangelogs [option...] old new-a new-b [out]

DESCRIPTION

       This program will use the 3 provided versions of the Debian changelog to generate a merged
       changelog file.  The resulting changelog is stored in the file out or output to the
       standard output if that parameter is not given.

       Each entry is identified by its version number and they are assumed to be not conflicting,
       they are simply merged in the right order (by decreasing version number).  When
       --merge-prereleases is used, the part of the version number after the last tilde is
       dropped so that 1.0-1~exp1 and 1.0-1~exp5 are considered to be the same entry.  When the
       same version is available in both new-a and new-b, a standard line-based 3-way merge is
       attempted (provided that the module Algorithm::Merge is available — it's part of the
       package libalgorithm-merge-perl — otherwise you get a global conflict on the content of
       the entry).

       This program was introduced in dpkg 1.15.7.

OPTIONS

       --merge-unreleased
           Ignore the version number when the entries are marked as UNRELEASED (since dpkg
           1.21.0).

           This is useful when you have diverging development for versions that have not yet been
           released.  For instance 2.1-1 is released, then development happens for the new 2.2-1
           and then for 2.3-1, where it makes sense to just end with a coalesced entry for 2.3-1
           including all the development done in 2.2-1.

       -m, --merge-prereleases
           Drop the part after the last tilde in the version number when doing version comparison
           to identify if two entries are supposed to be the same or not.

           This is useful when you keep using the same changelog entry but you increase its
           version number regularly.  For instance, you might have 2.3-1~exp1, 2.3-1~exp2, ...
           until the official release 2.3-1 and they are all the same changelog entry that has
           evolved over time.

       --help
           Show the usage message and exit.

       --version
           Show the version and exit.

ENVIRONMENT

       DPKG_COLORS
           Sets the color mode (since dpkg 1.18.5).  The currently accepted values are: auto
           (default), always and never.

       DPKG_NLS
           If set, it will be used to decide whether to activate Native Language Support, also
           known as internationalization (or i18n) support (since dpkg 1.19.0).  The accepted
           values are: 0 and 1 (default).

LIMITATIONS

       Anything that is not parsed by Dpkg::Changelog is lost during the merge.  This might
       include stuff like comments which were not supposed to be there, etc.

INTEGRATION WITH GIT

       If you want to use this program to merge Debian changelog files in a git repository, you
       have first to register a new merge driver in .git/config or ~/.gitconfig:

        [merge "dpkg-mergechangelogs"]
           name = debian/changelog merge driver
           driver = dpkg-mergechangelogs -m %O %A %B %A

       Then you have to setup the merge attribute for the debian/changelog file either in
       .gitattributes in the repository itself, or in .git/info/attributes:

        debian/changelog merge=dpkg-mergechangelogs