This file documents how file and revision properties are used in
cvs2svn.

cvs2svn allows arbitrary properties to be associated with CVSFile and
CVSRevision instances.  These properties are combined to form the
effective properties for each CVSRevision.  Properties set in a
CVSRevision take precedence over properties set in the corresponding
CVSFile.

These properties can be set very flexibly by FilePropertySetter and
RevisionPropertySetter objects, which in turn can be implemented
arbitrarily and set via the conversion configuration file.  Several
types of PropertySetters are already provided, and examples of there
use are shown in the example configuration files.  The properties are
determined early in the conversion and are retained for the duration
of the conversion.

CVSFile.properties holds properties that do not change for the life of
the file; for example, whether keywords should be expanded in the file
contents.

CVSRevision.properties holds properties that can vary from one file
revision to another.  The only current example of a revision property
is the cvs2svn:rev-num property.

Properties whose names start with underscore are reserved for the
internal use of cvs2svn.

The properties can be used by backends for any purpose.  Currently,
they are used for two purposes:

1. Passing RevisionReaders information about how a file revision's
   contents should be transformed before being written to the new VCS.
   Please note that this does not necessarily correspond to how the
   revision contents will look after being checked out of the new VCS;
   for example, Subversion requires keywords to be *unexpanded* in the
   dumpfile stream if Subversion is going to expand them.  These
   properties are:

       _keyword_handling -- How should RCS keywords be handled?

           'untouched' -- The keywords should be output literally as
               they are recorded in the RCS file.  Please note that
               this results in the keywords' being expanded the way
               they were when the revision was checked *in* to CVS,
               which typically reflects how CVS expanded them when the
               *previous* revision was checked *out* of CVS.  This
               mode is appropriate for binary files.

           'collapsed' -- The keywords should be collapsed in the
               output; e.g., "$Author: jrandom $" -> "$Author$".  This
               mode is appropriate for output of non-binary files to
               Subversion (because Subversion re-expands the keywords
               itself) and might be useful for text files for other
               VCSs if you would like this history to be "clean" of
               keywords.

           'expanded' -- The keywords should be expanded in the output
               the same way as CVS would expand keywords when checking
               out the revision; e.g., "$Author$" -> "$Author: jrandom
               $".  If this value is used, keywords are expanded
               regardless of whether CVS considers the file to be a
               text file.  This mode might be useful for outputting
               text files to other VCSs if you would like the content
               of historical revisions to be as similar as possible to
               the content as it would be checked out of CVS.

           'deleted' -- The keywords and their values (and some
               surrounding whitespace?) should be deleted entirely.
               NOT YET IMPLEMENTED.

           'replaced' -- The keywords should be deleted entirely and
               replaced by their values; e.g., "$Author$" ->
               "jrandom", like CVS's "-kv" option.  This is not a very
               useful feature, but is listed for completeness.  NOT
               YET IMPLEMENTED.

       _eol_fix -- Should end-of-line sequences be made uniform before
           committing to the target VCS?  If this property is set to a
           non-empty value, then every end-of-line character sequence
           ('\n', '\r\n', or '\r') is converted to the specified value
           (which should obviously be a valid end-of-line character
           sequence).  If this property is not set, then the
           end-of-line character sequences are output literally as
           they are recorded in the RCS file.

2. cvs2svn: Specifying Subversion versioned properties.  Any
   properties that do not start with an underscore are converted into
   Subversion versioned properties on the associated file.  By this
   mechanism, arbitrary Subversion properties can be set.  A number of
   PropertySetters are provided to set common Subversion properties
   such as svn:mime-type, svn:eol-style, svn:executable, and
   svn:keywords.  Other properties can be set via the
   AutoPropsPropertySetter or by implementing custom PropertySetters.