diff

[greg@kroah.com (Greg KH)]

On Mon, Mar 13, 2017 at 05:57:14PM +1100, Tobin C. Harding wrote:
> On occasions diff output does not render the same as it does when
> editing a file. For example, while removing checkpatch tab warning
> the following diff was generated
> 
> -#define KS_WLAN_SET_WPS_ENABLE                 SIOCIWFIRSTPRIV + 4
> -#define KS_WLAN_GET_WPS_ENABLE                 SIOCIWFIRSTPRIV + 5
> +#define KS_WLAN_SET_WPS_ENABLE         SIOCIWFIRSTPRIV + 4
> +#define KS_WLAN_GET_WPS_ENABLE         SIOCIWFIRSTPRIV + 5
> 
> However when editing the file the alignment was not changed, just tabs
> were inserted instead of spaces.
> 
> I had the same thing happen a few days ago (reproduced here from
> memory)
> 
> -static void foo(struct bar *barp, struct baz *bazp)
> +static void foo(struct bar *barp,
> +               struct baz *bazp)

You missed that there are really tabs in the real diff, you used all
spaces here.

> {
>         ...
> 
> When editing the file the two s's in struct were aligned but not in
> the diff output. I reapplied this patch to a clean tree and it applied
> correctly.
> 
> How do maintainers visually parse this if the output is not identical in the
> diff and the file once applied?

We are used to reading diffs :)

we can edit them by hand as well, but that's a skill best left alone...

greg k-h