On Thu, Oct 19, 2017 at 2:39 PM, Jeff King <peff@xxxxxxxx> wrote:
> On Thu, Oct 19, 2017 at 02:31:20PM -0700, Stefan Beller wrote:
>
>> > This is unlikely to ever come up in practice since our line
>> > boundaries generally come from calling strlen() in the first
>> > place.
>>
>> get_string_hash is called from
>> prepare_entry, which in turn is called from
>> add_lines_to_move_detection or mark_color_as_moved
>> diff_flush_patch_all_file_pairs
>>
>> that constructs the arguments in
>> diff_flush_patch
>> run_diff
>> run_diff_cmd
>> builtin_diff (part "/* Crazy xdl interfaces.. */")
>> xdi_diff_outf( fn_out_consume as arg!)
>> xdi_diff
>> xdl_diff
>> xdl_call_hunk_func
>> -> fn_out_consume(cb, line, len)
>>
>> xdl_call_hunk_func however uses pointer arithmetic instead
>> of strlen. So I think this sentence is not a good idea to put in
>> the commit message.
>>
>> It may not occur in practice, due to binary files detection using
>> NUL as a signal, but conceptually our move-colored(!) diffs
>> should be compatible with NULs with this patch now.
>
> Good catch. I just skimmed over all the diff_emit_* functions, which use
> strlen(). But at the bottom is emit_add_line(), which has a real length
> marker from xdiff.
Doh!
There is diff_emit_submodule_* but I presume you meant
emit_diff_* actually as there the strlen is legit, as we generate
known non-NUL data to print.
The submodule output may get mangled in diff_emit_submodule_{add,del}
as the input is coming from user data.
> I agree we wouldn't see NULs in general, but this is maybe fixing "diff
> --color-moved -a". I dunno. It's probably not worth digging too much,
> since it seems like the right thing to do regardless.
I agree, that this digging seems not worth it; I was just agitated at
the seemingly incorrect commit message.
Thanks,
Stefan
>
> -Peff
