From dce5b3eb0c3814802bade97009739d8a9b2f6a91 Mon Sep 17 00:00:00 2001
From: emv <emv@opencascade.com>
Date: Thu, 4 Oct 2018 13:25:06 +0300
Subject: [PATCH] 0030198: Regression to 7.1.0: BRepAlgoAPI_Fuse unlimited
 memory usage

When refining the mesh to achieve required deflection (IntPolyh_Triangle::MultipleMiddleRefinement) limit the number of new triangles to avoid infinite loop.
Test case for the issue.
---
 src/IntPolyh/IntPolyh_Triangle.cxx |  6 ++++-
 tests/bugs/modalg_7/bug30198       | 39 ++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 1 deletion(-)
 create mode 100644 tests/bugs/modalg_7/bug30198

diff --git a/src/IntPolyh/IntPolyh_Triangle.cxx b/src/IntPolyh/IntPolyh_Triangle.cxx
index 4308a8c21f..527da5e232 100644
--- a/src/IntPolyh/IntPolyh_Triangle.cxx
+++ b/src/IntPolyh/IntPolyh_Triangle.cxx
@@ -574,10 +574,14 @@ void IntPolyh_Triangle::MultipleMiddleRefinement(const Standard_Real theRefineCr
 {
   // Number of triangles before refinement of current triangle
   const Standard_Integer FinTTInit = TTriangles.NbItems();
+  // Criteria to stop splitting - double of the initial number of triangles,
+  // i.e. allow each triangle to be split at least once. Add a constant
+  // to allow the splits of triangles to be checked.
+  const Standard_Integer MaxNbTT = 2*FinTTInit + 1000;
   // Split the current triangle
   MiddleRefinement(theTriangleNumber, theSurface, TPoints, TTriangles, TEdges);
   // Refine the new triangles
-  for (Standard_Integer i = FinTTInit; i < TTriangles.NbItems(); ++i) {
+  for (Standard_Integer i = FinTTInit; i < TTriangles.NbItems() && i < MaxNbTT; ++i) {
     IntPolyh_Triangle& aTriangle = TTriangles[i];
     if(theBox.IsOut(aTriangle.BoundingBox(TPoints))) {
       aTriangle.SetIntersectionPossible(Standard_False);
diff --git a/tests/bugs/modalg_7/bug30198 b/tests/bugs/modalg_7/bug30198
new file mode 100644
index 0000000000..9499c324b7
--- /dev/null
+++ b/tests/bugs/modalg_7/bug30198
@@ -0,0 +1,39 @@
+puts "========"
+puts "0030198: Regression to 7.1.0: BRepAlgoAPI_Fuse unlimited memory usage"
+puts "========"
+puts ""
+
+restore [locate_data_file bug30198_src.brep] b1
+restore [locate_data_file bug30198_tool.brep] b2
+
+bclearobjects
+bcleartools
+baddobjects b1
+baddtools b2
+bfillds
+
+bapibop r0 0
+bapibop r1 1
+bapibop r2 2
+bapibop r3 3
+bapibop r4 4
+
+checkshape r0
+checknbshapes r0 -wire 33 -face 32 -shell 1 -solid 1
+checkprops r0 -s 46.2958 -v 11.2502
+
+checkshape r1
+checknbshapes r1 -wire 163 -face 151 -shell 1 -solid 1
+checkprops r1 -s  216.217 -v 62.6126
+
+checkshape r2
+checknbshapes r2 -wire 153 -face 142 -shell 2 -solid 2
+checkprops r2 -s 222.03 -v 47.9412
+
+checkshape r3
+checknbshapes r3 -wire 43 -face 41 -shell 1 -solid 1
+checkprops r3 -s 40.5104 -v 3.42122
+
+checksection r4 -r 0
+
+checkview -display r1 -2d -path ${imagedir}/${test_image}.png