0028113: BOPAlgo_Builder produces invalid shape

Fast rebuilding of the face is now avoided if its edges have been unified during the intersection.
Full rebuilding of the face is required in this case (using BuilderFace algorithm).

src/BOPAlgo/BOPAlgo_Builder_2.cxx

@@ -865,6 +865,10 @@ TopoDS_Face BuildDraftFace(const TopoDS_Face& theFace,
   // possibility of split.
   TopTools_DataMapOfShapeListOfShape aVerticesCounter;
 
+  // Check that the edges of the initial face have not been unified during intersection.
+  // Otherwise, it will be necessary to check validity of the new wires.
+  TopTools_MapOfShape aMEdges;
+
   // Update wires of the original face and add them to draft face
   TopoDS_Iterator aItW(theFace.Oriented(TopAbs_FORWARD));
   for (; aItW.More(); aItW.Next())
@@ -895,6 +899,8 @@ TopoDS_Face BuildDraftFace(const TopoDS_Face& theFace,
 
       // Check if the original edge is degenerated
       Standard_Boolean bIsDegenerated = BRep_Tool::Degenerated(aE);
+      // Check if the original edge is closed on the face
+      Standard_Boolean bIsClosed = BRep_Tool::IsClosed(aE, theFace);
 
       // Check for the splits of the edge
       const TopTools_ListOfShape* pLEIm = theImages.Seek(aE);
@@ -904,13 +910,14 @@ TopoDS_Face BuildDraftFace(const TopoDS_Face& theFace,
         if (!bIsDegenerated && HasMultiConnected(aE, aVerticesCounter))
           return TopoDS_Face();
 
+        // Check edges unification
+        if (!bIsClosed && !aMEdges.Add(aE))
+          return TopoDS_Face();
+
         aBB.Add(aNewWire, aE);
         continue;
       }
 
-      // Check if the original edge is closed on the face
-      Standard_Boolean bIsClosed = BRep_Tool::IsClosed(aE, theFace);
-
       TopTools_ListIteratorOfListOfShape aItLEIm(*pLEIm);
       for (; aItLEIm.More(); aItLEIm.Next())
       {
@@ -920,6 +927,10 @@ TopoDS_Face BuildDraftFace(const TopoDS_Face& theFace,
         if (!bIsDegenerated && HasMultiConnected(aSp, aVerticesCounter))
           return TopoDS_Face();
 
+        // Check edges unification
+        if (!bIsClosed && !aMEdges.Add(aSp))
+          return TopoDS_Face();
+
         aSp.Orientation(anOriE);
         if (bIsDegenerated)
         {

tests/bugs/modalg_7/bug28113_1

@@ -0,0 +1,47 @@
+puts "======="
+puts "OCC28113: BOPAlgo_Builder produces invalid shape"
+puts "======="
+puts ""
+
+
+restore [locate_data_file bug28113_shapes.brep] s
+explode s
+
+# fix the first shape in compound
+# 1. exclude s_1_3 from compsolid
+eval compound [lrange [explode s_1 so] 0 1] [lrange [explode s_1 so] 3 end] comp
+# fix SI in compound
+eval mkvolume v [explode comp f]
+checkshape v
+checknbshapes v -solid 18 -shell 18
+if {![regexp "OK" [bopcheck v]]} {
+  puts "Error: unable to rebuild the shape"
+}
+
+# create Compsolid
+shape s1 CS
+foreach s [explode v so] { add $s s1}
+
+# perform the operation
+bclearobjects
+bcleartools
+baddobjects s1
+baddtools s_2 s_3 s_4 s_5
+bfillds
+bbuild gf
+bsplit result
+
+foreach r {gf result} {
+  checkshape $r
+  if {![regexp "OK" [bopcheck $r]]} {
+    puts "Error: result is a self-interfering shape"
+  }
+}
+
+checknbshapes gf -wire 417 -face 417 -shell 91 -solid 90
+checkprops gf -s 259559 -v 690192
+
+checknbshapes result -wire 417 -face 417 -shell 90 -solid 90
+checkprops result -s 226564 -v 669028
+
+checkview -display result -2d -path ${imagedir}/${test_image}.png

tests/bugs/modalg_7/bug28113_2

@@ -0,0 +1,20 @@
+puts "======="
+puts "OCC28113: BOPAlgo_Builder produces invalid shape"
+puts "======="
+puts ""
+
+
+restore [locate_data_file bug28113_shapes_2.brep] s
+explode s
+bclearobjects
+bcleartools
+baddobjects s_1
+baddtools s_2
+bfillds
+bsplit result
+
+checkshape result
+checknbshapes result -wire 34 -face 34 -shell 3 -solid 3
+checkprops result -s 26451 -v 107642
+
+checkview -display result -2d -path ${imagedir}/${test_image}.png

tests/bugs/modalg_7/bug28123

@@ -26,7 +26,7 @@ foreach r {r0 r1 r2 r3 r4} {
 }
 
 checknbshapes r0 -wire 6 -face 6 -shell 1 -solid 1
-checkprops r0 -s 5.2 -v 0.42
+checkprops r0 -s 4.8 -v 0.405134
 
 checknbshapes r1 -wire 25 -face 25 -shell 1 -solid 1
 checkprops r1 -s 45921.2 -v 6839.09
@@ -37,6 +37,6 @@ checkprops r2 -s 45780.6 -v 6784.77
 checknbshapes r3 -wire 10 -face 10 -shell 2 -solid 2
 checkprops r3 -s 142.969 -v 39.5572
 
-checkprops r4 -l 14.2568
+checkprops r4 -l 14.8225
 
 checkview -display r2 -2d -path ${imagedir}/${test_image}.png