Re: [PATCH v2] checkpatch: add double empty line check

On Tue, Nov 20, 2012 at 06:22:24PM +0200, Eilon Greenstein wrote:

On Tue, 2012-11-20 at 16:14 +0000, Andy Whitcroft wrote:

quoted

On Tue, Nov 20, 2012 at 06:06:10PM +0200, Eilon Greenstein wrote:

quoted

I'm only testing the nextline if the current line is newly added. If I
got it right, when a line is newly added, the next line can be:
a. another new line
b. existing line (provided for context)
c. Does not exist since this is the end of the file (I missed this one
originally)

It cannot just jump to the next hunk and it cannot be a deleted line,
right?

Mostly that would be true.  If the hunk is the last hunk and adds lines
at the bottom of a file _and_ the context around it has blank lines then
something.  I think that would trip up this algorithm, reporting beyond
the end of the hunk perhaps.

I do not want to cause any perl warning, but adding a new segment that
ends with a new empty line above an existing empty line is something
that I want to catch - so checking the next line (even if it is not new)
is desired. Do you have other suggestions on how to implement something
like that?

I'm not saying that my patch is safe - I already missed a corner case
when adding a line at the end of the file, but I'm willing to run more
tests and see if I hit some perl warning. So how about running it on the
last X changes in the kernel git tree? How many tests are enough to get
reasonable confidant level?

I have been testing the patches there with some fake files to try and
catch these indeed.  I did incldue my take on how to solve this in
previous replies.

-apw