Re: [PATCH 1/3] xdiff: -W: relax end-of-file function detection

["René Scharfe" <l.s.r@web.de>]

Am 13.01.2017 um 17:15 schrieb Vegard Nossum:
> When adding a new function to the end of a file, it's enough to know
> that 1) the addition is at the end of the file; and 2) there is a
> function _somewhere_ in there.
>
> If we had simply been changing the end of an existing function, then we
> would also be deleting something from the old version.

That makes sense, thanks.

> This fixes the case where we add e.g.
>
> 	// Begin of dummy
> 	static int dummy(void)
> 	{
> 	}
>
> to the end of the file.

Without this patch the unchanged function before the added lines is 
shown in its entirety as (uncalled for) context.

>
> Cc: René Scharfe <l.s.r@web.de>
> Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
> ---
>  xdiff/xemit.c | 14 ++++++--------
>  1 file changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/xdiff/xemit.c b/xdiff/xemit.c
> index 7389ce4..8c88dbd 100644
> --- a/xdiff/xemit.c
> +++ b/xdiff/xemit.c
> @@ -183,16 +183,14 @@ int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
>
>  				/*
>  				 * We don't need additional context if
> -				 * a whole function was added, possibly
> -				 * starting with empty lines.
> +				 * a whole function was added.
>  				 */
> -				while (i2 < xe->xdf2.nrec &&
> -				       is_empty_rec(&xe->xdf2, i2))
> +				while (i2 < xe->xdf2.nrec) {
> +					if (match_func_rec(&xe->xdf2, xecfg, i2,
> +						dummy, sizeof(dummy)) >= 0)

Nit: I don't like the indentation here.  Giving "dummy" its own line is 
also not exactly pretty, but at least would allow the parameters to be 
aligned on the opening parenthesis.

> +						goto post_context_calculation;
>  					i2++;
> -				if (i2 < xe->xdf2.nrec &&
> -				    match_func_rec(&xe->xdf2, xecfg, i2,
> -						   dummy, sizeof(dummy)) >= 0)
> -					goto post_context_calculation;
> +				}
>
>  				/*
>  				 * Otherwise get more context from the
>