Re: [PATCH v1 9/9] diff --color-moved-ws: handle blank lines

>
> From: Phillip Wood <phillip.wood@dunelm.org.uk>
>
> When using --color-moved-ws=allow-indentation-change allow lines with
> the same indentation change to be grouped across blank lines. For now
> this only works if the blank lines have been moved as well, not for
> blocks that have just had their indentation changed.
>
> This completes the changes to the implementation of
> --color-moved=allow-indentation-change. Running
>
>   git diff --color-moved=allow-indentation-change v2.18.0 v2.19.0
>
> now takes 5.0s. This is a saving of 41% from 8.5s for the optimized
> version of the previous implementation and 66% from the original which
> took 14.6s.
>
> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
> ---
>
> Notes:
>     Changes since rfc:
>      - Split these changes into a separate commit.
>      - Detect blank lines when processing the indentation rather than
>        parsing each line twice.
>      - Tweaked the test to make it harder as suggested by Stefan.
>      - Added timing data to the commit message.
>
>  diff.c                     | 34 ++++++++++++++++++++++++++++---
>  t/t4015-diff-whitespace.sh | 41 ++++++++++++++++++++++++++++++++++----
>  2 files changed, 68 insertions(+), 7 deletions(-)
>
> diff --git a/diff.c b/diff.c
> index 89559293e7..072b5bced6 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -792,9 +792,11 @@ static void moved_block_clear(struct moved_block *b)
>         memset(b, 0, sizeof(*b));
>  }
>
> +#define INDENT_BLANKLINE INT_MIN