Fix LineString->getPoint(n) for M geometries (closes GH-1191)

libgeos · Nov 15, 2024 · 47e2308 · 47e2308
2 parents bf8a953 + 51c3b3d
commit 47e2308
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diff --git a/NEWS.md b/NEWS.md
@@ -13,6 +13,7 @@
   - GEOSLineSubstring, avoid crash with NaN length fraction (GH-1077, Dan Baston)
   - MinimumClearance, avoid crash on NaN inputs (GH-1079, Dan Baston)
   - Fix LineString->getPoint(n) for M geometries (GH-1191, @hsieyuan)
+  - Fix TopologyPreservingSimplifier/TaggedLineString to avoid jumping components (JTS-1096, Martin Davis)
 
 
 ## Changes in 3.12.2

diff --git a/src/simplify/TaggedLineString.cpp b/src/simplify/TaggedLineString.cpp
@@ -169,7 +169,7 @@ TaggedLineString::extractCoordinates(
 
     if(size) {
         for(std::size_t i = 0; i < size; i++) {
-            TaggedLineSegment* seg = segs[i];
+                TaggedLineSegment* seg = segs[i];
             assert(seg);
             pts->add(seg->p0);
         }
@@ -185,7 +185,6 @@ TaggedLineString::extractCoordinates(
 const Coordinate&
 TaggedLineString::getCoordinate(std::size_t i) const
 {
-
     return parentLine->getCoordinateN(i);
 }
 
@@ -198,6 +197,10 @@ TaggedLineString::size() const
 const Coordinate&
 TaggedLineString::getComponentPoint() const
 {
+    //-- when simplified use a valid coordinate
+    if (resultSegs.size() > 0) {
+        return resultSegs[0]->p0;
+    }
     return getParentCoordinates()->getAt(1);
 }