ENH: patchSet: wrong logic to compress points. See #1453.

src/sampling/sampledSet/patchEdge/patchEdgeSet.C

@@ -138,8 +138,9 @@ void Foam::patchEdgeSet::genSamples()
         origin_
     );
 
-    if (nMerged == 0)
+    if (nMerged == samplingPts.size())
     {
+        // Nothing merged
         setSamples
         (
             samplingPts,

src/sampling/sampledSet/patchEdge/patchEdgeSet.H

@@ -94,8 +94,12 @@ Usage
     \endtable
 
 Note
-    The ordering of the points is according to the distance to the specified
+    - The ordering of the points is according to the distance to the specified
     origin.
+    - Collocated points get merged if closer than SMALL (1e-15 in double prec).
+    (hardcoded). Collocated points can occur if patch points are exactly
+    on the sampling plane. Note that (in parallel) any point merging gets
+    done locally before sending to the master.
 
 SourceFiles
     patchEdgeSet.C