Use more precise bounds when testing overlap of temporal ranges.

For 2.3, references #4025

git-svn-id: http://svn.osgeo.org/postgis/branches/2.3@16421 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/NEWS b/NEWS
index 41406f7a9cdbbaff5c523f8f0b828ee82552d843..0999fd008b09b98caba42386a1e55d6787ce84eb 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,7 @@ PostGIS 2.3.7dev
   - #4003, lwpoly_construct_circle: Avoid division by zero (Raúl Marín Rodríguez)
   - #4020, Casting from box3d to geometry now returns correctly connected
            PolyhedralSurface (Matthias Bay)
+  - #4025, Incorrect answers for temporally "amost overlapping" ranges
 
 PostGIS 2.3.6
 2018/01/17

diff --git a/liblwgeom/lwlinearreferencing.c b/liblwgeom/lwlinearreferencing.c
index 5cb81bb21dfc5dbae1c5b99f4aa8a23e2b5fc1bb..8580e1befafbabac10ffa62b207f46ccfc27658f 100644 (file)
--- a/liblwgeom/lwlinearreferencing.c
+++ b/liblwgeom/lwlinearreferencing.c
@@ -1073,7 +1073,7 @@ lwgeom_tcpa(const LWGEOM *g1, const LWGEOM *g2, double *mindist)
 {
        LWLINE *l1, *l2;
        int i;
-       const GBOX *gbox1, *gbox2;
+       GBOX gbox1, gbox2;
        double tmin, tmax;
        double *mvals;
        int nmvals = 0;
@@ -1101,20 +1101,19 @@ lwgeom_tcpa(const LWGEOM *g1, const LWGEOM *g2, double *mindist)
                return -1;
        }
 
-       /* WARNING: these ranges may be wider than real ones */
-       gbox1 = lwgeom_get_bbox(g1);
-       gbox2 = lwgeom_get_bbox(g2);
-
-       assert(gbox1); /* or the npoints check above would have failed */
-       assert(gbox2); /* or the npoints check above would have failed */
+       /* We use lwgeom_calculate_gbox() instead of lwgeom_get_gbox() */
+       /* because we cannot afford the float rounding inaccuracy when */
+       /* we compare the ranges for overlap below */
+       lwgeom_calculate_gbox(g1, &gbox1);
+       lwgeom_calculate_gbox(g2, &gbox2);
 
        /*
         * Find overlapping M range
         * WARNING: may be larger than the real one
         */
 
-       tmin = FP_MAX(gbox1->mmin, gbox2->mmin);
-       tmax = FP_MIN(gbox1->mmax, gbox2->mmax);
+       tmin = FP_MAX(gbox1.mmin, gbox2.mmin);
+       tmax = FP_MIN(gbox1.mmax, gbox2.mmax);
 
        if ( tmax < tmin )
        {