Re: [PATCH] checkpatch: warn about hunks which only add blank lines

[Markus Armbruster <armbru@redhat.com>]

Thomas Huth <thuth@redhat.com> writes:

> On 31/07/2026 15.40, Denis V. Lunev wrote:
>> Patches sometimes carry a hunk whose entire content is one or two
>> added blank lines. It changes nothing, it makes the diff longer and
>> it survives review because nobody looks twice at a blank line. The
>> blank line itself is perfectly fine, the gratuitous hunk is not.
>
> Well, I wouldn't say that the blank line itself is fine. It depends.
> In source code, there normally should not be more than one empty line between code blocks, that's why I complained to the patch in your pull request.

For what it's worth, Python style *demands* two blank lines in places.
Here's what happens when I delete one of them:

    $ pycodestyle scripts/qapi/parser.py 
    scripts/qapi/parser.py:656:1: E302 expected 2 blank lines, found 1

Why?  PEP 8 "Style Guide for Python Code" section "Blank Lines":

--> Surround top-level function and class definitions with two blank
--> lines.

    Method definitions inside a class are surrounded by a single blank
    line.

    Extra blank lines may be used (sparingly) to separate groups of
    related functions. Blank lines may be omitted between a bunch of
    related one-liners (e.g. a set of dummy implementations).

    Use blank lines in functions, sparingly, to indicate logical
    sections.

    Python accepts the control-L (i.e. ^L) form feed character as
    whitespace; many tools treat these characters as page separators, so
    you may use them to separate pages of related sections of your
    file. Note, some editors and web-based code viewers may not
    recognize control-L as a form feed and will show another glyph in
    its place.

We run pycodestyle via flake8 from python/tests/linters.py.  Still not
part of "make check".

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