Merge #145283

145283: geo: fix index out of bounds for recently added builtin r=yuzefovich a=yuzefovich

Fixes: #144282
Fixes: #144446

Release note: None

Co-authored-by: Yahor Yuzefovich <[email protected]>

Author: craig[bot]

pkg/geo/geomfn/unary_operators.go

@@ -250,20 +250,18 @@ func CountVertices(t geom.T) int {
 // lineString does not have a z-coordinate.
 func length3DLineString(lineString *geom.LineString) (float64, error) {
 	lineCoords := lineString.Coords()
-	prevPoint := lineCoords[0]
-	lineLength := float64(0)
 	zIndex := lineString.Layout().ZIndex()
 	if zIndex < 0 || zIndex >= lineString.Stride() {
 		return 0, errors.AssertionFailedf("Z-Index for LINESTRING is out-of-bounds")
 	}
-	for i := 0; i < lineString.NumCoords(); i++ {
-		curPoint := lineCoords[i]
+	lineLength := float64(0)
+	for i := 1; i < len(lineCoords); i++ {
+		prevPoint, curPoint := lineCoords[i-1], lineCoords[i]
 		deltaX := curPoint.X() - prevPoint.X()
 		deltaY := curPoint.Y() - prevPoint.Y()
 		deltaZ := curPoint[zIndex] - prevPoint[zIndex]
 		distBetweenPoints := math.Sqrt(deltaX*deltaX + deltaY*deltaY + deltaZ*deltaZ)
 		lineLength += distBetweenPoints
-		prevPoint = curPoint
 	}
 
 	return lineLength, nil

pkg/sql/logictest/testdata/logic_test/geospatial_zm

@@ -388,6 +388,16 @@ SELECT ST_3DLength('LINESTRING(743238 2967416 1,743238 2967450 1,743265 2967450
 ----
 122.70471674145682
 
+query R
+SELECT ST_3DLength('010200008000000000':::GEOMETRY);
+----
+0
+
+query R
+SELECT ST_3DLength('01020000C000000000':::GEOMETRY);
+----
+0
+
 query TTT nosort
 SELECT
   encode(ST_AsTWKB(t, 5), 'hex'),