Warning about conflict markers - undocumented 'diff --check' feature & suggestion

A bug report and a suggestion:

`git diff --check` has been warning about conflict markers since 2008: https://marc.info/?l=git&m=122398500726634&w=2

This is an undocumented feature. The current documentation for the flag only mentions "whitespace errors".

This check will also be useful in `git add`, to prevent accidental staging of conflict markers. Perhaps it could be included, if not by default, then at least with a configuration setting.

Thoughts? Is this perhaps an existing feature that I'm missing? :)

-Ori

Ori Avtalion <ori@avtalion.name> writes:

Thanks for digging (even though I do not think the message you quoted has much to do with this).

04954043 (diff --check: detect leftover conflict markers, 2008-06-26) was the change that added this check to the "check whitespace breakage" codepath, which forgot to update the documentation.

And when 4f830390 (Documentation: git diff --check respects core.whitespace, 2011-06-22) rewrote the paragraph, it again didn't remember to update it to match the reality.

Care to try a patch?

On Tue, Mar 29, 2016 at 2:01 AM, Junio C Hamano <gitster@pobox.com> wrote:

Oops, you are correct! I had several tabs open digging through the archives and picked the wrong one :)

Yes. Will submit one soon. If my change introduces a few words that exceed asciidoc's ~72-char line width, should I reformat the entire paragraph? (thus making it had to identify what changed exactly)

Any thoughts on adding similar functionality to "git add"?

Ori Avtalion <ori@avtalion.name> writes:

You should try to minimize the damage, but shouldn't go overboard ;-)

I am not sure what "similar functionality" you are imagining.

"git add" does not show any changes, it just does what it was told to do. If the user is unsure, s/he should make it the habit to check what s/he is doing with "git diff".

On Tue, Mar 29, 2016 at 9:23 PM, Junio C Hamano <gitster@pobox.com> wrote:

I was thinking of an off-by-default setting where git-add outright refuses to stage changes that do not pass "diff --check". I understand if that's a big deviation from the spirit of the tool, and perhaps not a good idea.

Signed-off-by: Ori Avtalion <ori@avtalion.name>
---
 Documentation/diff-options.txt | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)