convert: check for failed svn import in debugsvnlog and abort cleanly 'hg debugsvnlog' failed with a crash when using the uninitialized transport in get_log_child if the import of the svn libraries had failed. 'convert' should never get as far as launching 'hg debugsvnlog' if the svn libraries are missing, but by launching a subprocess there is risk that the environment is mangled so the second import fails. It is in principle also possible to launch the command manually.

convert: accept Subversion 'file:///c%3A/svnrepo' syntax on Windows Subversion can handle ':' quoted as '%3A' but urllib.url2pathname can't and Mercurial thus rejected some valid subversions URLs. This particular case will now be handled by some preprocessing before handing it over to urllib.url2pathname. This is tested by 0413f68da85c when test-convert-svn-source.t and test-convert-svn-move.t can be run on Windows.