convert/svn: make sink recover gracefully from empty changeset
Otherwise when processing a changeset that in fact changes no files
(perhaps due to bug in import from CVS) can get something like:
unexpected svn output:
abort: unable to cope with svn output
Bug report and patch draft by Jesse Glick <jesse.glick@sun.com>
% convert before branching point
initializing destination A-r3-hg repository
scanning source...
sorting...
converting...
3 removeb
2 changeaa
1 branch, changeaaa
0 addc,changeaaaa
o 3 addc,changeaaaa files: a c
|
o 2 branch, changeaaa files: a
|
o 1 changeaa files: a
|
o 0 removeb files: a
% convert before branching point
initializing destination A-r4-hg repository
scanning source...
sorting...
converting...
2 changeaa
1 branch, changeaaa
0 addc,changeaaaa
o 2 addc,changeaaaa files: a c
|
o 1 branch, changeaaa files: a
|
o 0 changeaa files: a
% convert at branching point
initializing destination A-r5-hg repository
scanning source...
sorting...
converting...
1 branch, changeaaa
0 addc,changeaaaa
o 1 addc,changeaaaa files: a c
|
o 0 branch, changeaaa files: a
% convert last revision only
initializing destination A-r6-hg repository
scanning source...
sorting...
converting...
0 addc,changeaaaa
o 0 addc,changeaaaa files: a c