From 5089a57d658a105c6b90da6d256c95601542f2ed Mon Sep 17 00:00:00 2001
From: azv <azv@opencascade.com>
Date: Fri, 21 Apr 2017 18:12:39 +0300
Subject: [PATCH] Fix the frequently appeared "conflicting constraints" message
 when the point is coincident with the feature and its extremity.

---
 .../SketchSolver_ConstraintCoincidence.cpp    | 40 +++++++++++++++++++
 .../SketchSolver_ConstraintCoincidence.h      |  1 +
 2 files changed, 41 insertions(+)

diff --git a/src/SketchSolver/SketchSolver_ConstraintCoincidence.cpp b/src/SketchSolver/SketchSolver_ConstraintCoincidence.cpp
index a2c3357b6..88de9a68c 100644
--- a/src/SketchSolver/SketchSolver_ConstraintCoincidence.cpp
+++ b/src/SketchSolver/SketchSolver_ConstraintCoincidence.cpp
@@ -5,6 +5,33 @@
 #include <PlaneGCSSolver_Tools.h>
 #include <PlaneGCSSolver_UpdateCoincidence.h>
 
+#include <SketchPlugin_Arc.h>
+#include <SketchPlugin_Line.h>
+
+static void getCoincidentFeatureExtremities(const ConstraintPtr& theConstraint,
+                                            const StoragePtr& theStorage,
+                                            EntityWrapperPtr theExtremities[2])
+{
+  for (int i = 0; i < CONSTRAINT_ATTR_SIZE; ++i) {
+    AttributeRefAttrPtr aRefAttr = theConstraint->refattr(SketchPlugin_Constraint::ATTRIBUTE(i));
+    if (!aRefAttr || !aRefAttr->isObject())
+      continue;
+
+    FeaturePtr aFeature = ModelAPI_Feature::feature(aRefAttr->object());
+    if (!aFeature)
+      continue;
+
+    if (aFeature->getKind() == SketchPlugin_Line::ID()) {
+      theExtremities[0] = theStorage->entity(aFeature->attribute(SketchPlugin_Line::START_ID()));
+      theExtremities[1] = theStorage->entity(aFeature->attribute(SketchPlugin_Line::END_ID()));
+    } else if (aFeature->getKind() == SketchPlugin_Arc::ID()) {
+      theExtremities[0] = theStorage->entity(aFeature->attribute(SketchPlugin_Arc::START_ID()));
+      theExtremities[1] = theStorage->entity(aFeature->attribute(SketchPlugin_Arc::END_ID()));
+    }
+  }
+}
+
+
 void SketchSolver_ConstraintCoincidence::process()
 {
   cleanErrorMsg();
@@ -58,6 +85,9 @@ void SketchSolver_ConstraintCoincidence::getAttributes(
       myType = CONSTRAINT_PT_ON_CIRCLE;
     else
       myErrorMsg = SketchSolver_Error::INCORRECT_ATTRIBUTE();
+
+    // obtain extremity points of the coincident feature for further checking of multi-coincidence
+    getCoincidentFeatureExtremities(myBaseConstraint, myStorage, myFeatureExtremities);
   } else
     myErrorMsg = SketchSolver_Error::INCORRECT_ATTRIBUTE();
 }
@@ -68,6 +98,16 @@ void SketchSolver_ConstraintCoincidence::notify(const FeaturePtr&      theFeatur
   PlaneGCSSolver_UpdateCoincidence* anUpdater =
       static_cast<PlaneGCSSolver_UpdateCoincidence*>(theUpdater);
   bool isAccepted = anUpdater->checkCoincidence(myAttributes.front(), myAttributes.back());
+
+  // additionally check the point is coincident to extremity of coincident feature
+  if (myFeatureExtremities[0] && myFeatureExtremities[1]) {
+    EntityWrapperPtr aPoint =
+        myAttributes.front()->type() == ENTITY_POINT ? myAttributes.front() : myAttributes.back();
+
+    for (int i = 0; i < 2; ++i)
+      isAccepted = isAccepted && !anUpdater->isPointOnEntity(aPoint, myFeatureExtremities[i]);
+  }
+
   if (isAccepted) {
     if (!myInSolver) {
       myInSolver = true;
diff --git a/src/SketchSolver/SketchSolver_ConstraintCoincidence.h b/src/SketchSolver/SketchSolver_ConstraintCoincidence.h
index 83ec15b40..0a3ea83e8 100644
--- a/src/SketchSolver/SketchSolver_ConstraintCoincidence.h
+++ b/src/SketchSolver/SketchSolver_ConstraintCoincidence.h
@@ -41,6 +41,7 @@ protected:
 
 protected:
   bool myInSolver; ///< shows the constraint is added to the solver
+  EntityWrapperPtr myFeatureExtremities[2]; ///< extremities of a feature, a point is coincident to
 };
 
 #endif
-- 
2.39.2