verify: report first bad changeset
- add linkrev and file arguments to err
- track lowest reported linkrev in err
- find linkrev in a couple cases
- sort linkrevs when reporting a bunch of errors against a file
- tidy up lots of messages
- make more robust against damaged indexes
- report first bad changeset if an error is encountered
% file replaced with directory
adding a
% should fail - would corrupt dirstate
abort: file 'a' in dirstate clashes with 'a/a'
% directory replaced with file
adding a/a
% should fail - would corrupt dirstate
abort: directory 'a' already in dirstate
% directory replaced with file
adding b/c/d
% should fail - would corrupt dirstate
abort: directory 'b' already in dirstate