Created attachment 367450 [details, diff] Patch for new rsync ebuild. rsync bundles its own modified version of zlib by default. As of 3.1.0, however, the option to compile against an unmodified zlib (such as the system zlib) is available. The developers' intention is to eventually make this option the default, but for now, it can be manually enabled with a configure flag: --with-included-zlib=no. I propose exposing this option as a use flag. Attached is a diff against the current rsync-3.1.0 ebuild which I believe does this.
doesn't seem like anything has really changed: zlib/README.rsync: Specific changes that have been made to zlib for rsync include: - add Z_INSERT_ONLY to allow for efficient history updating without actually emitting any data. This is used to compress the matched blocks that don't cross the wire, which gives better compression ratios on the literal data. As a result of the first item, the streams from rsync's version of zlib are *not compatible* with those produced by the upstream version of rsync. In other words, if you link rsync against your system's copy, it will not be able to interoperate with any other version if the -z option is used. (Sorry. Sometimes standard is better than better.)