Re: [PATCH] diff: update conflict handling for whitespace to issue a warning

"Usman Akinyemi via GitGitGadget" [off-list ref] writes:

From: Usman Akinyemi <redacted>

Modify the conflict resolution between tab-in-indent and
indent-with-non-tab to issue a warning instead of terminating
the operation with `die()`. Update the `git diff --check` test to
capture and verify the warning message output.

Hmph, giving a warning against these conflicting setting (instead of
dying) and continuing _may_ make sense sometimes, but it is unclear
which one should survive.

I do not think of a scenario in which it makes much sense to let the
program warn only on one but not the other one.  Perhaps disabling
both, if we were to do the "warn and keep going, instead of dying",
may make some more sense than that.  I dunno.