Update to 2.40.61. Ok tonio@. Set LICENSE.

Changes in Version 2.40.61

   Changes since 2.40.1:
     * Added "BelowPath" patterns, that match a path as well as all paths
       below (convenient to use with nodeletion,update,creationpartial
       preferences)
     * Added a "fat" preference that makes Unison use the right options
       when one of the replica is on a FAT filesystem.
     * Allow "prefer/force=newer" even when not synchronizing
       modification times. (The reconciler will not be aware of the
       modification time of unchanged files, so the synchronization
       choices of Unison can be different from when "times=true", but the
       behavior remains sane: changed files with the most recent
       modification time will be propagated.)
     * Minor fixes and improvements:
          + Compare filenames up to decomposition in case sensitive mode
            when one host is running MacOSX and the unicode preference is
            set to true.
          + Rsync: somewhat faster compressor
          + Make Unicode the default on all architectures (it was only
            the default when a Mac OS X or Windows machine was involved).

   Changes since 2.32:
     * Major enhancement: Unicode support.
          + Unison should now handle unicode filenames correctly on all
            platforms.
          + This functionality is controlled by a new preference unicode.
          + Unicode mode is now the default when one of the hosts is
            under Windows or MacOS. This may make upgrades a bit more
            painful (the archives cannot be reused), but this is a much
            saner default.
     * Partial transfer of directories. If an error occurs while
       transferring a directory, the part transferred so far is copied
       into place (and the archives are updated accordingly). The
       "maxerrors" preference controls how many transfer error Unison
       will accept before stopping the transfer of a directory (by
       default, only one). This makes it possible to transfer most of a
       directory even if there are some errors. Currently, only the first
       error is reported by the GUIs.
       Also, allow partial transfer of a directory when there was an
       error deep inside this directory during update detection. At the
       moment, this is only activated with the text and GTK UIs, which
       have been modified so that they show that the transfer is going to
       be partial and so that they can display all errors.
     * Improvement to the code for resuming directory transfers:
          + if a file was not correctly transferred (or the source has
            been modified since, with unchanged size), Unison performs a
            new transfer rather than failing
          + spurious files are deleted (this can happen if a file is
            deleted on the source replica before resuming the transfer;
            not deleting the file would result in it reappearing on the
            target replica)
     * Experimental streaming protocol for transferring file contents
       (can be disabled by setting the directive "stream" to false): file
       contents is transfered asynchronously (without waiting for a
       response from the destination after each chunk sent) rather than
       using the synchronous RPC mechanism. As a consequence:
          + Unison now transfers the contents of a single file at a time
            (Unison used to transfer several contents simultaneously in
            order to hide the connection latency.)
          + the transfer of large files uses the full available bandwidth
            and is not slowed done due to the connection latency anymore
          + we get performance improvement for small files as well by
            scheduling many files simultaneously (as scheduling a file
            for transfer consume little ressource: it does not mean
            allocating a large buffer anymore)
     * Changes to the internal implementation of the rsync algorithm:
          + use longer blocks for large files (the size of a block is the
            square root of the size of the file for large files);
          + transmit less checksum information per block (we still have
            less than one chance in a hundred million of transferring a
            file incorrectly, and Unison will catch any transfer error
            when fingerprinting the whole file)
          + avoid transfer overhead (which was 4 bytes per block)
       For a 1G file, the first optimization saves a factor 50 on the
       amount of data transferred from the target to the source (blocks
       are 32768 bytes rather than just 700 bytes). The two other
       optimizations save another factor of 2 (from 24 bytes per block
       down to 10).
     * Implemented an on-disk file fingerprint cache to speed-up update
       detection after a crash: this way, Unison does not have do
       recompute all the file fingerprints from scratch.
          + When Unison detects that the archive case-sensitivity mode
            does not match the current settings, it populates the
            fingerprint cache using the archive contents. This way,
            changing the case-sensitivity mode should be reasonably fast.
     * New preferences "noupdate=root", "nodeletion=root",
       "nocreation=root" that prevent Unison from performing files
       updates, deletions or creations on the given root. Also 'partial'
       versions of 'noupdate', 'nodeletion' and 'nocreation'
     * Limit the number of simultaneous external copy program ("copymax"
       preference)
     * New "links" preference. When set to false, Unison will report an
       error on symlinks during update detection. (This is the default
       when one host is running Windows but not Cygwin.) This is better
       than failing during propagation.
     * Added a preference "halfduplex" to force half-duplex communication
       with the server. This may be useful on unreliable links (as a more
       efficient alternative to "maxthreads = 1").
     * Renamed preference "pretendwin" to "ignoreinodenumbers" (an alias
       is kept for backwards compatibility).
     * Ignore one-second differences when synchronizing modification
       time. (Technically, this is an incompatible archive format change,
       but it is backward compatible. To trigger a problem, a user would
       have to synchronize modification times on a filesystem with a
       two-second granularity and then downgrade to a previous version of
       Unison, which does not work well in such a case. Thus, it does not
       seem worthwhile to increment the archive format number, which
       would impact all users.)
     * Do not keep many files simultaneously opened anymore when the
       rsync algorithm is in use.
     * Add "ignorearchives" preference to ignore existing archives (to
       avoid forcing users to delete them manually, in situations where
       one archive has gotten deleted or corrupted).
     * Mac OS
          + fixed rsync bug which could result in an "index out of
            bounds" error when transferring resource forks.
          + Fixed bug which made Unison ignore finder information and
            resource fork when compiled to 64bit on Mac OSX.
          + should now be 64 bit clean (the Growl framework is not up to
            date, though)
          + Made the bridge between Objective C and Ocaml code GC
            friendly (it was allocating ML values and putting them in an
            array which was not registered with the GC)
          + use darker grey arrows (patch contributed by Eric Y. Kow)
     * GTK user interface
          + assistant for creating profiles
          + profile editor
          + pop up a summary window when the replicas are not fully
            synchronized after transport
          + display estimated remaining time and transfer rate on the
            progress bar
          + allow simultaneous selection of several items
          + Do not reload the preference file before a new update
            detection if it is unchanged
          + disabled scrolling to the first unfinished item during
            transport. It goes way too fast when lot of small files are
            synchronized, and it makes it impossible to browse the file
            list during transport.
          + take into account the "height" preference again
          + the internal list of selected reconciler item was not always
            in sync with what was displayed (GTK bug?); workaround
            implemented
          + Do not display "Looking for change" messages during
            propagation (when checking the targe is unchanged) but only
            during update detection
          + Apply patch to fix some crashes in the OSX GUI, thanks to
            Onne Gorter.
     * Text UI
          + During update detection, display status by updating a single
            line rather than generating a new line of output every so
            often. Should be less confusing.
     * Windows
          + Fastcheck is now the default under Windows. People mostly use
            NTFS nowadays and the Unicode API provides an equivalent to
            inode numbers for this filesystem.
          + Only use long UNC path for accessing replicas (as '..' is not
            handled with this format of paths, but can be useful)
          + Windows text UI: now put the console into UTF-8 output mode.
            This is the right thing to do when in Unicode mode, and is no
            worse than what we had previously otherwise (the console use
            some esoteric encoding by default). This only works when
            using a Unicode font instead of the default raster font.
          + Don't get the home directory from environment variable HOME
            under Windows (except for Cygwin binaries): we don't want the
            behavior of Unison to depends on whether it is run from a
            Cygwin shell (where HOME is set) or in any other way (where
            HOME is usually not set).
     * Miscellaneous fixes and improvements
          + Made a server waiting on a socket more resilient to
            unexpected lost connections from the client.
          + Small patch to property setting code suggested by Ulrich
            Gernkow.
          + Several fixes to the change transfer functions (both the
            internal ones and external transfers using rsync). In
            particular, limit the number of simultaneous transfer using
            an rsync (as the rsync algorithm can use a large amount of
            memory when processing huge files)
          + Keep track of which file contents are being transferred, and
            delay the transfer of a file when another file with the same
            contents is currently being transferred. This way, the second
            transfer can be skipped and replaced by a local copy.
          + Experimental update detection optimization: do not read the
            contents of unchanged directories
          + When a file transfer fails, turn off fastcheck for this file
            on the next sync.
          + Fixed bug with case insensitive mode on a case sensitive
            filesystem:
               o if file "a/a" is created on one replica and directory
                 "A" is created on the other, the file failed to be
                 synchronized the first time Unison is run afterwards, as
                 Unison uses the wrong path "a/a" (if Unison is run
                 again, the directories are in the archive, so the right
                 path is used);
               o if file "a" appears on one replica and file "A" appears
                 on the other with different contents, Unison was unable
                 to synchronize them.
          + Improved error reporting when the destination is updated
            during synchronization: Unison now tells which file has been
            updated, and how.
          + Limit the length of temporary file names
          + Case sensitivity information put in the archive (in a
            backward compatible way) and checked when the archive is
            loaded
          + Got rid of the 16mb marshalling limit by marshalling to a
            bigarray.
          + Resume copy of partially transferred files.


(wiz)