diffstat: properly count lines starting in '--' or '++' (issue5479) Lines that start in '--' or '++' were previously not counted as deletions or additions in diffstat, resulting in incorrect addition/deletion counts. The bug was present if the start of the line, combined with the diff character resulted in '---' or '+++'. diffstatdata will now track, for each file, if it has moved pas the header section by looking for a line beginning with '@@'. Once that has happened, lines beginning with '-' or '+' will be counted for deletions and additions. Once a line beginning with 'diff' is found, the process starts over.