<div dir="ltr"><div><div>Hi Paolo,<br><br></div>I've encountered differing opinions on the validity of repeated vertices. The ticket linked below summarizes the "invalid" argument, and includes a link to the "valid" argument:<br><a href="https://trac.osgeo.org/postgis/ticket/3425">https://trac.osgeo.org/postgis/ticket/3425</a><br><br></div>Dan<br><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Feb 14, 2018 at 2:17 PM, Paolo Cavallini <span dir="ltr"><<a href="mailto:cavallini@faunalia.it" target="_blank">cavallini@faunalia.it</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi all,<br>
we noticed two strange things in the behaviour of ST_IsValid:<br>
* repeated vertices are not considered invalid<br>
* in case of multiple intersections on a same polygon, only the first<br>
one is reported.<br>
Is there an explanation for this?<br>
Thanks.<br>
<span class="HOEnZb"><font color="#888888">--<br>
Paolo Cavallini - <a href="http://www.faunalia.eu" rel="noreferrer" target="_blank">www.faunalia.eu</a><br>
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