add: introduce a warning message for non-portable filenames (issue2756) (BC) On POSIX platforms, the 'add', 'addremove', 'copy' and 'rename' commands now warn if a file has a name that can't be checked out on Windows. Example: $ hg add con.xml warning: filename contains 'con', which is reserved on Windows: 'con.xml' $ hg status A con.xml The file is added despite the warning. The warning is ON by default. It can be suppressed by setting the config option 'portablefilenames' in section 'ui' to 'ignore' or 'false': $ hg --config ui.portablefilenames=ignore add con.xml $ hg sta A con.xml If ui.portablefilenames is set to 'abort', then the command is aborted: $ hg --config ui.portablefilenames=abort add con.xml abort: filename contains 'con', which is reserved on Windows: 'con.xml' On Windows, the ui.portablefilenames config setting is irrelevant and the command is always aborted if a problematic filename is found.