[bug-diffutils] Re: diff --ignore-all-space doesn't ignore newlines after all

[Jim Meyering]

address@hidden wrote:
> I forgot to X-debbugs-cc: address@hidden . They should please
> look at
> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=613319

Contrary to documentation:

       The `-w' and `--ignore-all-space' options are stronger than `-b'.
    They ignore difference even if one file has white space where the other
    file has none.  "White space" characters include tab, newline, vertical

--ignore-all-space does not make diff ignore newlines:

    $ diff -u --ignore-all-space <(seq 3) <(seq 3|fmt)
    --- /proc/self/fd/11    2011-02-19 14:25:31.479058914 +0100
    +++ /proc/self/fd/12    2011-02-19 14:25:31.478058883 +0100
    @@ -1,3 +1 @@
    -1
    -2
    -3
    +1 2 3

Perhaps because diff is fundamentally line-oriented.
I haven't delved into this.

If you want that functionality, you might prefer wdiff.