From 80b120ed40d0141c08170c5b8bbb11d6a2ededcd Mon Sep 17 00:00:00 2001
From: azv <azv@opencascade.com>
Date: Mon, 10 Nov 2014 08:28:57 +0300
Subject: [PATCH] Issue #196: Implemented verification of zero distance in
 SketchSolver

---
 src/SketchSolver/SketchSolver_ConstraintGroup.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/SketchSolver/SketchSolver_ConstraintGroup.cpp b/src/SketchSolver/SketchSolver_ConstraintGroup.cpp
index 7eff7e79b..d6550ed52 100644
--- a/src/SketchSolver/SketchSolver_ConstraintGroup.cpp
+++ b/src/SketchSolver/SketchSolver_ConstraintGroup.cpp
@@ -241,6 +241,10 @@ bool SketchSolver_ConstraintGroup::changeConstraint(
       theConstraint->data()->attribute(SketchPlugin_Constraint::VALUE()));
   if (aDistAttr) {
     aDistance = aDistAttr->value();
+    // Issue #196: checking the positivity of the distance constraint
+    if (aDistance < tolerance &&
+       (aConstrType == SLVS_C_PT_PT_DISTANCE || aConstrType == SLVS_C_PT_LINE_DISTANCE))
+      return false;
     // SketchPlugin circle defined by its radius, but SolveSpace uses constraint for diameter
     if (aConstrType == SLVS_C_DIAMETER)
       aDistance *= 2.0;
-- 
2.39.2