Where have markers to be drawn in custom-shapes?

[Regina Henschel]

Hi Miklos,

Miklos Vajna schrieb am 21.09.2021 um 08:35:
> Hi Regina,
> 
> On Mon, Sep 13, 2021 at 07:35:10PM +0200, Regina Henschel <rb.henschel at t-online.de> wrote:
>> I cannot determine where to draw markers for the draw:enhanced-path of a
>> custom-shape. This question is not about path-objects and not about SVG, but
>> only about custom-shapes.
>>
>> ODF has no rule for it yet.
> 
> I would default to what LibreOffice does today, just to avoid
> compatibility problems. What do you think?

I think, that we should not use the current behavior of LibreOffice 
because it is inconsistent. I have already reported
https://bugs.documentfoundation.org/show_bug.cgi?id=144390

I have created an OASIS issue
https://issues.oasis-open.org/browse/OFFICE-4111
That has a file attached with problematic situation.

In my opinion there should be this behavior:
[In the following I mean "sub-path" in ODF sense, not in LO internal sense.]
(1) A sub-path which is closed by a command Z and not continued, should 
never have markers. Currently LO draws markers if there exists a 
sub-path after the closed sub-path which has e.g. a line. I mean command 
sequences like MLLZML.
(2) A sub-path which is closed and continued, should have marker start. 
This situation is currently wrong implemented. I mean command sequences 
like MLLZLL are wrongly drawn by LO. A command Z does not end a sub-path.
(3) A sub-path were accidentally "first point = last point" is currently 
drawn without markers (if not continued), although having "first point = 
last point" does not close the sub-path. The equivalence of "first point 
= last point" to "closed" is only an (problematic) implementation detail 
for path-objects, but an enhanced-path has a dedicated "close" command 
and the path might not end with the "close" command.
(4) Different sets of sub-paths should be treated independently. I mean 
sequences like MLLZNMLML.

In regard to "compatibility": MS Office behaves already different on 
ODF-files than LibreOffice, whereby I think, that MS Office is neither a 
role model as it has inconsistencies too. Different versions of LO would 
only be affected in non-primitive shapes. I think (but I have not 
examined all predefined shapes), the predefined shapes have no 
problematic path definitions. Closed sub-path and separate lines are in 
different sets, so that problem (1) does not occur. And situations (2) 
and (3) do not exist in the predefined shapes.

Kind regards,
Regina