From 0e7304f3cc0a6c855a922071b6286c1e74e0ecc7 Mon Sep 17 00:00:00 2001
From: eap <eap@opencascade.com>
Date: Tue, 13 Nov 2018 19:28:05 +0300
Subject: [PATCH] 54462: Hexa(ijk) fails on a composite block with a
 degenerated edge (note 0509712)

---
 .../StdMeshers_CompositeHexa_3D.cxx           | 41 +++++++++++++++----
 1 file changed, 33 insertions(+), 8 deletions(-)

diff --git a/src/StdMeshers/StdMeshers_CompositeHexa_3D.cxx b/src/StdMeshers/StdMeshers_CompositeHexa_3D.cxx
index a023ae623..3d3a28d6a 100644
--- a/src/StdMeshers/StdMeshers_CompositeHexa_3D.cxx
+++ b/src/StdMeshers/StdMeshers_CompositeHexa_3D.cxx
@@ -312,13 +312,15 @@ namespace
     if ( !TopExp::CommonVertex( E1, E2, V )) return false;
 
     const SMDS_MeshNode* n = SMESH_Algo::VertexNode( V, mesh.GetMeshDS() );
-    if ( !n ) return false;
+    if ( !n ) return SMESH_Algo::IsContinuous( E1, E2 ); // meshed by "composite segment"
 
     SMESHDS_SubMesh* sm = mesh.GetSubMeshContaining( F )->GetSubMeshDS();
     if ( !sm ) return false;
 
     int nbQuads = 0;
     SMDS_ElemIteratorPtr fIt = n->GetInverseElementIterator(SMDSAbs_Face);
+    if ( !fIt->more() )
+      return SMESH_Algo::IsContinuous( E1, E2 ); // meshed by "composite segment"
     while ( fIt->more() )
     {
       const SMDS_MeshElement* f = fIt->next();
@@ -332,6 +334,28 @@ namespace
     return nbQuads == 2;
   }
 
+  //================================================================================
+  /*!
+   * \brief Return true if a vertex holds a node and this node is used by some quadrangle
+   */
+  //================================================================================
+
+  // bool isMeshedVertex( TopoDS_Vertex&     V,
+  //                      const SMESH_Mesh&  mesh )
+  // {
+  //   const SMDS_MeshNode* n = SMESH_Algo::VertexNode( V, mesh.GetMeshDS() );
+  //   if ( !n ) return false;
+    
+  //   SMDS_ElemIteratorPtr fIt = n->GetInverseElementIterator(SMDSAbs_Face);
+  //   while ( fIt->more() )
+  //   {
+  //     const SMDS_MeshElement* f = fIt->next();
+  //     if ( f->NbCornerNodes() == 4 )
+  //       return true;
+  //   }
+  //   return false;
+  // }
+
   //================================================================================
   /*!
    * \brief Finds VERTEXes located at block corners
@@ -896,13 +920,7 @@ bool _QuadFaceGrid::Init(const TopoDS_Face& f, SMESH_Mesh& mesh)
       if ( SMESH_Algo::isDegenerated( sideEdges.back() ))
         continue;
       while ( !edges.empty() ) {
-        if ( SMESH_Algo::IsContinuous( sideEdges.back(), edges.front() )) {
-          sideEdges.splice( sideEdges.end(), edges, edges.begin());
-        }
-        else if ( SMESH_Algo::IsContinuous( sideEdges.front(), edges.back() )) {
-          sideEdges.splice( sideEdges.begin(), edges, --edges.end());
-        }
-        else if ( isContinuousMesh( sideEdges.back(), edges.front(), f, mesh )) {
+        if ( isContinuousMesh( sideEdges.back(), edges.front(), f, mesh )) {
           sideEdges.splice( sideEdges.end(), edges, edges.begin());
         }
         else if ( isContinuousMesh( sideEdges.front(), edges.back(), f, mesh )) {
@@ -1946,6 +1964,13 @@ bool _FaceSide::StoreNodes(SMESH_Mesh&                   mesh,
                                                 nodes);
     if ( !ok ) return false;
 
+    // skip nodes on VERTEXes not included in faces
+    if ( !nodes.begin()->second->GetInverseElementIterator(SMDSAbs_Face)->more() )
+      nodes.erase( nodes.begin() );
+    if ( !nodes.empty() &&
+         !nodes.rbegin()->second->GetInverseElementIterator(SMDSAbs_Face)->more() )
+      nodes.erase( --nodes.end() );
+
     bool forward = ( edge->Orientation() == TopAbs_FORWARD );
     if ( reverse ) forward = !forward;
     if ( forward )
-- 
2.30.2