From fd6d6d0f67c98c095d38c8ff1a4845ca50278844 Mon Sep 17 00:00:00 2001
From: Sandro Santilli <strk@keybit.net>
Date: Tue, 12 Jun 2012 12:34:23 +0000
Subject: [PATCH] Clearer error on setting an geometry to an invalid one
 (#1774)

Include testcase

git-svn-id: http://svn.osgeo.org/postgis/trunk@9899 b70326c6-7e19-0410-871a-916f4a2858ee
---
 topology/sql/sqlmm.sql.in.c                      | 7 ++++++-
 topology/test/regress/st_changeedgegeom.sql      | 8 ++++++++
 topology/test/regress/st_changeedgegeom_expected | 2 ++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/topology/sql/sqlmm.sql.in.c b/topology/sql/sqlmm.sql.in.c
index 8bb8bd31e..b6d0b3110 100644
--- a/topology/sql/sqlmm.sql.in.c
+++ b/topology/sql/sqlmm.sql.in.c
@@ -2547,7 +2547,7 @@ BEGIN
       WHERE p.sequence = CASE WHEN m.sequence-1 < 1 THEN cnt
                          ELSE m.sequence-1 END
     ), (
-      SELECT p.edge AS prev FROM edgestar p                                           WHERE p.sequence = ((m.sequence)%cnt)+1
+      SELECT p.edge AS prev FROM edgestar p WHERE p.sequence = ((m.sequence)%cnt)+1
     ) ]
   FROM edgestar m
   WHERE edge = anedge
@@ -2642,7 +2642,12 @@ BEGIN
     --       (should be part of isomorphism checking)
     range := ST_MakePolygon(oldedge.geom);
     iscw := ST_OrderingEquals(range, ST_ForceRHR(range));
+
+    IF ST_NumPoints(ST_RemoveRepeatedPoints(acurve)) < 3 THEN
+      RAISE EXCEPTION 'Invalid edge (no two distinct vertices exist)';
+    END IF;
     range := ST_MakePolygon(acurve);
+
     IF iscw != ST_OrderingEquals(range, ST_ForceRHR(range)) THEN
       RAISE EXCEPTION 'Edge twist at node %',
         ST_AsText(ST_StartPoint(oldedge.geom));
diff --git a/topology/test/regress/st_changeedgegeom.sql b/topology/test/regress/st_changeedgegeom.sql
index b00239ebe..f995e47c4 100644
--- a/topology/test/regress/st_changeedgegeom.sql
+++ b/topology/test/regress/st_changeedgegeom.sql
@@ -17,6 +17,14 @@ SELECT topology.ST_ChangeEdgeGeom('city_data', 25,
 SELECT topology.ST_ChangeEdgeGeom('city_data', 3,
   'LINESTRING(25 30, 20 36, 20 38, 25 35)');
 
+-- Non-simple edge
+SELECT topology.ST_ChangeEdgeGeom('city_data', 1,
+  'LINESTRING(8 30, 9 30, 8 30)');
+
+-- Dimensionally collapsed edge (#1774)
+SELECT topology.ST_ChangeEdgeGeom('city_data', 1,
+  'LINESTRING(8 30, 8 30, 8 30)');
+
 -- Non-existent edge (#979)
 SELECT topology.ST_ChangeEdgeGeom('city_data', 666,
   'LINESTRING(25 30, 20 36, 20 38, 25 35)');
diff --git a/topology/test/regress/st_changeedgegeom_expected b/topology/test/regress/st_changeedgegeom_expected
index fb7476559..34525f93f 100644
--- a/topology/test/regress/st_changeedgegeom_expected
+++ b/topology/test/regress/st_changeedgegeom_expected
@@ -8,6 +8,8 @@ T1|Edge 25 changed
 ERROR:  SQL/MM Spatial exception - start node not geometry start point.
 ERROR:  SQL/MM Spatial exception - end node not geometry end point.
 ERROR:  SQL/MM Spatial exception - geometry crosses a node
+ERROR:  SQL/MM Spatial exception - curve not simple
+ERROR:  Invalid edge (no two distinct vertices exist)
 ERROR:  SQL/MM Spatial exception - non-existent edge 666
 ERROR:  SQL/MM Spatial exception - geometry crosses edge 1
 T2|Edge 5 changed
-- 
2.40.0