+ bool undoLastEnabled() const;
+ /**
+ * Prepare revision rev of the file into newly created temporary file
+ * and save the filename into parameter f.
+ * Parameter rev can be either revision number or negative number
+ * which is interpreted as how many revision back from the current
+ * one do we want. rev=0 is reserved for the last (committed) revision.
+ * We need rev to be string, since in various VCS revision is not integer.
+ * If RCS addressed by a single number, it is automatically used
+ * as the last number in the whole revision specification (it applies
+ * for retrieving normal revisions (rev>0) or backtracking (rev<0).
+ */
+ bool prepareFileRevision(std::string const & rev, std::string & f);
+ /// Does the current VC supports this operation?
+ bool prepareFileRevisionEnabled();