0030392: XCAFDoc_GraphNode doesn't copy backward links

src/XCAFDoc/XCAFDoc_GraphNode.cxx

@@ -378,6 +378,8 @@ void XCAFDoc_GraphNode::Paste(const Handle(TDF_Attribute)& into,
     if (!func.IsNull())
     {
       intof->SetFather(func);
+      if (func->ChildIndex(this) && !func->ChildIndex(intof))
+        func->SetChild(intof);
     }
   }
 
@@ -391,6 +393,8 @@ void XCAFDoc_GraphNode::Paste(const Handle(TDF_Attribute)& into,
     if (!func.IsNull())
     {
       intof->SetChild(func);
+      if (func->FatherIndex(this) && !func->FatherIndex(intof))
+        func->SetFather(intof);
     }
   }
   intof->SetGraphID(myGraphID);

tests/perf/de/bug23979

@@ -1,58 +0,0 @@
-puts "=========="
-puts "0023979: Performance problem of STEP export for large files"
-puts "=========="
-puts ""
-
-cpulimit 100
-
-set n 100
-set m 100
-
-puts "Preparing compound of [expr $n * $m] prisms"
-
-autodisplay 0
-compound c
-chrono h restart
-for {set i 0} {$i < $n} {incr i} {
-  for {set j 0} {$j < $m} {incr j} {
-    set xbase [expr $i*10]
-    set ybase [expr $j*10]
-    set size 5
-    vertex v1 $xbase $ybase 0
-    vertex v2 [expr $xbase+$size] $ybase 0
-    vertex v3 [expr $xbase+0.5*$size] [expr $ybase+0.866*$size] 0
-    edge e1 v1 v2
-    edge e2 v2 v3
-    edge e3 v3 v1
-    wire w e1 e2 e3
-    mkplane f w
-    prism p f 0 0 10
-    add p c
-  }
-}
-chrono h stop counter "Constructing shape"
-
-meminfo
-
-puts "Converting data to STEP"
-newmodel
-chrono h restart
-stepwrite 0 c
-chrono h stop counter "Conversion to STEP"
-
-meminfo
-
-puts "Saving to file"
-chrono h restart
-set outfile ${imagedir}/bug23979.stp
-writeall $outfile
-chrono h stop counter "Saving file"
-
-puts "COUNTER File size (MiB): [expr [file size $outfile] / 1024 / 1024]"
-file delete -force $outfile
-
-meminfo
-
-puts "COUNTER Peak Page File Size (MiB): [expr [meminfo swappeak] / 1024 / 1024]"
-
-puts ""