[bug#70169] [PATCH v2 09/12] maint: Remove %%CreationDate from generated EPS files

[Janneke Nieuwenhuizen]

Ludovic Courtès writes:

> Janneke Nieuwenhuizen <janneke@gnu.org> skribis:
>
>> * doc/local.mk (.dot.eps, png.eps): Remove %%CreationDate.  Split single 
>> shell
>> command into separate recipe lines, prefixed by $(AM_V_at).
>>
>> Change-Id: I5a03485c19c72f0c46411815c51290e52a8e5399
>> ---
>>  doc/local.mk | 12 ++++++++----
>>  1 file changed, 8 insertions(+), 4 deletions(-)
>>
>> diff --git a/doc/local.mk b/doc/local.mk
>> index c355bec8d7..60e36091ce 100644
>> --- a/doc/local.mk
>> +++ b/doc/local.mk
>> @@ -152,12 +152,16 @@ DOT_OPTIONS =                                  \
>>      mv "$(srcdir)/$@.tmp" "$(srcdir)/$@"
>>  
>>  .dot.eps:
>> -    $(AM_V_DOT)$(DOT) -Teps $(DOT_OPTIONS) < "$<" > "$(srcdir)/$@.tmp"; \
>> -    mv "$(srcdir)/$@.tmp" "$(srcdir)/$@"
>> +    $(AM_V_DOT)$(DOT) -Teps $(DOT_OPTIONS) < "$<" > "$(srcdir)/$@.tmp"
>> +    $(AM_V_at)grep -v ^%%CreationDate: "$(srcdir)/$@.tmp" > 
>> "$(srcdir)/$@.tmp2"
>> +    $(AM_V_at)rm -f "$(srcdir)/$@.tmp"
>> +    $(AM_V_at)mv "$(srcdir)/$@.tmp2" "$@"
>
> Apparently ‘dot’ (GraphViz) does not emit a ‘CreationDate’ header.

Ah, good catch.

> Should we drop this change and add a line like this above the ‘mv’ line:

Probably I just copied the grep to remove it without much looking or
thinking :)

>   @if grep -q CreationDate "$@.tmp"; then false; else true; fi
>
> to be on the safe side?

Let's do that, I'm adding it as

    $(AM_V_at)! grep -q %%CreationDate "$(srcdir)/$@.tmp"

in v3.

>>  .png.eps:
>> -    $(AM_V_GEN)convert "$<" "$@-tmp.eps"; \
>> -    mv "$@-tmp.eps" "$@"
>> +    $(AM_V_GEN)convert "$<" "$@-tmp.eps"
>> +    $(AM_V_at)grep -v ^%%CreationDate: "$@-tmp.eps" > "$@-tmp2.eps"
>> +    $(AM_V_at)rm -f "$@-tmp.eps"
>> +    $(AM_V_at)mv "$@-tmp2.eps" "$@"
>
> Looking into the code of ImageMagick, I see:
>
>         timer=GetMagickTime();
>         (void) FormatMagickTime(timer,MaxTextExtent,date);
>         (void) FormatLocaleString(buffer,MaxTextExtent,
>           "%%%%CreationDate: %s\n",date);
>
> where ‘GetMagickTime’ honors ‘SOURCE_DATE_EPOCH’.  Should we set
> ‘SOURCE_DATE_EPOCH’ and avoid the ‘grep’ trick?

Good catch; and it already works.

> OTOH, an argument to keep this patch as-is is that it’ll resist to
> changes in ImageMagick/GraphViz.  So maybe the comments above aren’t
> that relevant.

Well, I like what we have now better; it's a bit sharper/cleaner anyway.

Thanks!
Janneke