From e64622331f0d16e29689c51f3fff6be638af2092 Mon Sep 17 00:00:00 2001
From: aml <aml@opencascade.com>
Date: Tue, 17 May 2016 07:24:57 +0300
Subject: [PATCH] 0027493: [Regression relative to OCCT 7.0.0] Extrema_ExtCC
 does not set flag "IsParallel" equal to true for the overlapped curves

Check for infinite solutions now starts from two solutions.
Test case is added.
---
 src/Extrema/Extrema_GenExtCC.gxx |  3 +--
 tests/bugs/moddata_3/bug27493    | 25 +++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 2 deletions(-)
 create mode 100644 tests/bugs/moddata_3/bug27493

diff --git a/src/Extrema/Extrema_GenExtCC.gxx b/src/Extrema/Extrema_GenExtCC.gxx
index 2c9c4ed187..1b2d45a19a 100644
--- a/src/Extrema/Extrema_GenExtCC.gxx
+++ b/src/Extrema/Extrema_GenExtCC.gxx
@@ -335,8 +335,7 @@ void Extrema_GenExtCC::Perform()
 
   // Avoid mark parallel case when have duplicates out of tolerance.
   // Bad conditioned task: bug25635_1, bug23706_10, bug23706_13.
-  const Standard_Integer aMinNbInfSol = 100;
-  if (aPnts.Size() >= aMinNbInfSol)
+  if (aPnts.Size() >= 2)
   {
     isParallel = Standard_True;
     for(Standard_Integer anIdx = aPnts.Lower(); anIdx <= aPnts.Upper() - 1; anIdx++)
diff --git a/tests/bugs/moddata_3/bug27493 b/tests/bugs/moddata_3/bug27493
new file mode 100644
index 0000000000..ec8195e6bd
--- /dev/null
+++ b/tests/bugs/moddata_3/bug27493
@@ -0,0 +1,25 @@
+puts "============"
+puts "OCC27493"
+puts "============"
+puts ""
+#########################################################################
+# [Regression relative to OCCT 7.0.0] Extrema_ExtCC does not set flag "IsParallel" equal to true for the overlapped curves
+#########################################################################
+
+restore [locate_data_file bug27493.brep] anEdges
+explode anEdges
+mkcurve c1 anEdges_1
+mkcurve c2 anEdges_2
+
+# Check infinite solutions flag value
+set info [extrema c1 c2]
+if { [regexp "Infinite number of extremas" ${info}] != 1 } {
+    puts "Error : Infinite solution flag have incorrect value"
+}
+
+# Check extrema distance
+regexp {distance = +([-0-9.+eE]+)} $info full aDist
+set absTol 1.0e-9
+set relTol 0.001
+set aDist_Exp 0.0
+checkreal "Distance value check" $aDist $aDist_Exp $absTol $relTol