RFR: 8009824: webrev.ksh generated jdk.patch files do not handle renames, copies, and shouldn't be applied

[Jim Gish]

Please review 
http://cr.openjdk.java.net/~jgish/Bug8009824-UpdateWebrevToUseHgExport/ 
<http://cr.openjdk.java.net/%7Ejgish/Bug8009824-UpdateWebrevToUseHgExport/>

This change to webrev.ksh replaces the current method for generating a 
patch with one that uses hg export -g, preserving copy, move and rename 
operations.  The current method results in a patch which does not 
properly account for these file operations and cannot be safely applied.

As a result of this change, a valid changeset is generated that can be 
safely applied by a committer (reducing the burden on and decreasing the 
chance of mistakes by non-committers when preparing webrevs and 
subsequent changesets to be sent to committers for pushing).

Note that the new method can only be used when there are committed 
changes.  If webrev is used against uncommitted changes in a users 
workspace, the old method of generating the patch is still used. 
(Another bug, another day :-))

Thanks,
    Jim

-- 
Jim Gish | Consulting Member of Technical Staff | +1.781.442.0304
Oracle Java Platform Group | Core Libraries Team
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Burlington, MA 01803
jim.gish at oracle.com