[postgis-tickets] r16839 - St_AsMVTGeom: Avoid type changes due to validation

[Raul]

Author: algunenano
Date: 2018-09-24 03:06:13 -0700 (Mon, 24 Sep 2018)
New Revision: 16839

Modified:
   branches/2.4/NEWS
   branches/2.4/postgis/mvt.c
   branches/2.4/regress/mvt.sql
   branches/2.4/regress/mvt_expected
Log:
St_AsMVTGeom: Avoid type changes due to validation

Closes #4181


Modified: branches/2.4/NEWS
===================================================================
--- branches/2.4/NEWS	2018-09-24 02:50:10 UTC (rev 16838)
+++ branches/2.4/NEWS	2018-09-24 10:06:13 UTC (rev 16839)
@@ -3,6 +3,7 @@
 
   * Bug Fixes and Enhancements
   - #4160, Use qualified names in topology extension install (Raúl Marín)
+  - #4181, St_AsMVTGeom: Avoid type changes due to validation (Raúl Marín)
 
 
 PostGIS 2.4.5

Modified: branches/2.4/postgis/mvt.c
===================================================================
--- branches/2.4/postgis/mvt.c	2018-09-24 02:50:10 UTC (rev 16838)
+++ branches/2.4/postgis/mvt.c	2018-09-24 10:06:13 UTC (rev 16839)
@@ -734,8 +734,19 @@
 
 	/* if polygon(s) make valid and force clockwise as per MVT spec */
 	if (lwgeom_out->type == POLYGONTYPE ||
-	    lwgeom_out->type == MULTIPOLYGONTYPE) {
-	    lwgeom_out = lwgeom_make_valid(lwgeom_out);
+	    lwgeom_out->type == MULTIPOLYGONTYPE)
+	{
+		lwgeom_out = lwgeom_make_valid(lwgeom_out);
+
+		/* Drop type changes to play nice with MVT renderers */
+		if (!(lwgeom_out->type == POLYGONTYPE ||
+		      lwgeom_out->type == MULTIPOLYGONTYPE ||
+		      lwgeom_out->type == COLLECTIONTYPE))
+		{
+			lwgeom_free(lwgeom_out);
+			return NULL;
+		}
+
 		/* Because we are in image coordinates, we need to go to CCW in */
 		/* order to get a CW output in image space */
 		lwgeom_force_clockwise(lwgeom_out);
@@ -749,8 +760,18 @@
 		lwgeom_out = lwgeom_homogenize(lwgeom_out);
 		/* if polygon(s) make valid and force clockwise as per MVT spec */
 		if (lwgeom_out->type == POLYGONTYPE ||
-		    lwgeom_out->type == MULTIPOLYGONTYPE) {
-		    lwgeom_out = lwgeom_make_valid(lwgeom_out);
+		    lwgeom_out->type == MULTIPOLYGONTYPE)
+		{
+			lwgeom_out = lwgeom_make_valid(lwgeom_out);
+
+			/* Drop type changes to play nice with MVT renderers */
+			if (!(lwgeom_out->type == POLYGONTYPE ||
+				lwgeom_out->type == MULTIPOLYGONTYPE))
+			{
+				lwgeom_free(lwgeom_out);
+				return NULL;
+			}
+
 			/* Because we are in image coordinates, we need to go to CCW in */
 			/* order to get a CW output in image space */
 			lwgeom_force_clockwise(lwgeom_out);

Modified: branches/2.4/regress/mvt.sql
===================================================================
--- branches/2.4/regress/mvt.sql	2018-09-24 02:50:10 UTC (rev 16838)
+++ branches/2.4/regress/mvt.sql	2018-09-24 10:06:13 UTC (rev 16839)
@@ -43,6 +43,14 @@
 	'POINT EMPTY'::geometry,
 	'BOX(0 0,2 2)'::box2d));
 
+-- Geometry type change
+SELECT 'PG44', ST_AsEWKT(ST_AsMVTGeom(
+	'SRID=3857;MULTIPOLYGON(((-8238038.43842083 4974073.00356281,-8238058.59985694 4974035.91194892,-8238046.74211362 4974077.68076013,-8238038.43842083 4974073.00356281)))'::geometry,
+	'SRID=3857;POLYGON((-8242969.13027341 4975133.29702555,-8242969.13027341 4970241.3272153,-8238077.16046316 4970241.3272153,-8238077.16046316 4975133.29702555,-8242969.13027341 4975133.29702555))'::geometry,
+	4096,
+	16,
+	true));
+
 -- geometry encoding tests
 SELECT 'TG1', encode(ST_AsMVT(q, 'test', 4096, 'geom'), 'base64') FROM (SELECT 1 AS c1,
     ST_Normalize(ST_AsMVTGeom(ST_GeomFromText('POINT(25 17)'),

Modified: branches/2.4/regress/mvt_expected
===================================================================
--- branches/2.4/regress/mvt_expected	2018-09-24 02:50:10 UTC (rev 16838)
+++ branches/2.4/regress/mvt_expected	2018-09-24 10:06:13 UTC (rev 16839)
@@ -8,6 +8,7 @@
 PG8|MULTIPOLYGON(((5 4096,10 4096,10 4091,5 4096)),((0 4096,0 4101,5 4096,0 4096)))
 PG9|POLYGON((0 0,0 4096,4096 4096,4096 0,0 0))
 PG10|
+PG44|
 TG1|GiEKBHRlc3QSDBICAAAYASIECTLePxoCYzEiAigBKIAgeAI=
 TG2|GiMKBHRlc3QSDhICAAAYASIGETTcPwECGgJjMSICKAEogCB4Ag==
 TG3|GiYKBHRlc3QSERICAAAYAiIJCQCAQArQD88PGgJjMSICKAEogCB4Ag==