stringutil: edit comment to reflect actual data type name In development the data type used to hold an email/name pair was called a "mailmaptup" since it was implemented as a namedtuple. The implementation has since been changed to use an @attr.s decorated class named mailmapping. This commit changes a comment to reflect this change. Differential Revision: https://phab.mercurial-scm.org/D3004

stringutil: improve check for failed mailmap line parsing The existing check for a bad mailmap file entry fails with inputs like b'>@<'. This commit adds a function to check if a sufficient amount of information has been parsed from a mailmap file entry. At minimum, one email must be found (assumed to be the commit email). If email is not empty and no names are found, then there must be two emails. If there are at least one email and name, the mapping is valid. Differential Revision: https://phab.mercurial-scm.org/D3003

stringutil: rename local email/names variables to their plural forms email and name variables are renamed to emails and names (respectively). This is because the email variable name shadows the email function within the stringutil module. Since we are renaming email, we also rename name for consistency. Differential Revision: https://phab.mercurial-scm.org/D3002