Hi Duy,

On Sun, 24 Mar 2019, Nguyễn Thái Ngọc Duy wrote:

> While at there, move exit() back to the caller. It's easier to see the
> flow that way than burying it in diff-no-index.c

I just noticed that this commit message is missing more than just a
trailing period. It does not explain the change of behavior: previously,
`GIT_EXTERNAL_DIFF=heya git diff --no-index a b` would silently ignore the
external diff, it would have required an explicit `--ext-diff` to pick it
up.

After this change, it is necessary to pass `--no-ext-diff` to reinstate
the original behavior.

While this might seem like a desirable change, it is a
backwards-incompatible change and would do with a *lot* more of a message
to users whose scripts now potentially break.

Ciao,
Johannes