The patch works mostly as one would expect, with the exception of a few
considerations that are worth mentioning here.
Like GNU grep, this patch ignores --only-matching when --invert (-v) is
given. There is a sensible answer here, but parity with the behavior of
other tools is preferred.
Because a line might contain more than one match, there are special
considerations pertaining to when to print line headers, newlines, and
how to increment the match column offset. The line header and newlines
are handled as a special case within the main loop to avoid polluting
the surrounding code with conditionals that have large blocks.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>