[postgis-tickets] r16263 - Encoded Polyline of EMPTY

[Darafei]

Author: komzpa
Date: 2018-01-12 00:18:39 -0800 (Fri, 12 Jan 2018)
New Revision: 16263

Modified:
   trunk/NEWS
   trunk/liblwgeom/cunit/cu_out_encoded_polyline.c
   trunk/liblwgeom/lwout_encoded_polyline.c
Log:
Encoded Polyline of EMPTY

Closes #3982
Closes https://github.com/postgis/postgis/pull/189


Modified: trunk/NEWS
===================================================================
--- trunk/NEWS	2018-01-11 22:09:35 UTC (rev 16262)
+++ trunk/NEWS	2018-01-12 08:18:39 UTC (rev 16263)
@@ -33,6 +33,8 @@
            (Darafei Praliaskouski)
   - #3971, ST_ClusterKMeans now uses better initial seed (Darafei Praliaskouski)
   - #3977, ST_ClusterKMeans is now faster and simpler (Darafei Praliaskouski)
+  - #3982, ST_AsEncodedPolyline supports LINESTRING EMPTY and MULTIPOINT EMPTY
+           (Darafei Praliaskouski)
 
 PostGIS 2.4.0
 2017/09/30

Modified: trunk/liblwgeom/cunit/cu_out_encoded_polyline.c
===================================================================
--- trunk/liblwgeom/cunit/cu_out_encoded_polyline.c	2018-01-11 22:09:35 UTC (rev 16262)
+++ trunk/liblwgeom/cunit/cu_out_encoded_polyline.c	2018-01-12 08:18:39 UTC (rev 16263)
@@ -46,17 +46,18 @@
 		"33.6673 38.6972,33.6626 38.6871)",
 		5,
 		"k~fkFsvolEbe at bVvVzJb~@j\\");
-	return;
 
 	/* Linestring */
 	do_encoded_polyline_test(
 		"LINESTRING(-120.2 38.5,-120.95 40.7,-126.453 43.252)",
 		5,
 		"_p~iF~ps|U_ulLnnqC_mqNvxq`@");
+	do_encoded_polyline_test("LINESTRING EMPTY", 5, "");
 
 	/* MultiPoint */
 	do_encoded_polyline_test(
 		"MULTIPOINT(-120.2 38.5,-120.95 40.7)", 5, "_p~iF~ps|U_ulLnnqC");
+	do_encoded_polyline_test("MULTIPOINT EMPTY", 5, "");
 }
 
 static void

Modified: trunk/liblwgeom/lwout_encoded_polyline.c
===================================================================
--- trunk/liblwgeom/lwout_encoded_polyline.c	2018-01-11 22:09:35 UTC (rev 16262)
+++ trunk/liblwgeom/lwout_encoded_polyline.c	2018-01-12 08:18:39 UTC (rev 16263)
@@ -69,18 +69,27 @@
 {
 	int i;
 	const POINT2D* prevPoint;
-	int* delta = lwalloc(2 * sizeof(int) * pa->npoints);
+	int* delta;
 	char* encoded_polyline = NULL;
 	stringbuffer_t* sb;
 	double scale = pow(10, precision);
 
+	/* Empty input is empty string */
+	if (pa->npoints == 0) {
+		encoded_polyline = lwalloc(1 * sizeof(char));
+		encoded_polyline[0] = 0;
+		return encoded_polyline;
+	}
+
+	delta = lwalloc(2 * sizeof(int) * pa->npoints);
+
 	/* Take the double value and multiply it by 1x10^precision, rounding the
 	 * result */
 	prevPoint = getPoint2d_cp(pa, 0);
 	delta[0] = round(prevPoint->y * scale);
 	delta[1] = round(prevPoint->x * scale);
 
-	/*  points only include the offset from the previous point */
+	/* Points only include the offset from the previous point */
 	for (i = 1; i < pa->npoints; i++)
 	{
 		const POINT2D* point = getPoint2d_cp(pa, i);