From 727dc9fa9e22e13bd585ece9fba0860fa3d321e1 Mon Sep 17 00:00:00 2001
From: Abdullah Tahiri <abdullah.tahiri.yo@gmail.com>
Date: Sat, 6 Feb 2021 06:19:49 +0100
Subject: [PATCH] Sketcher: Fix wrong diameter reference constraint value when
 blocked

====================================================================

Fixes:
https://forum.freecadweb.org/viewtopic.php?p=474276#p474276
---
 src/Mod/Sketcher/App/Sketch.cpp       | 25 ++++++++++++++++++++++++-
 src/Mod/Sketcher/App/planegcs/GCS.cpp |  8 ++++----
 src/Mod/Sketcher/App/planegcs/GCS.h   |  4 ++--
 3 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/src/Mod/Sketcher/App/Sketch.cpp b/src/Mod/Sketcher/App/Sketch.cpp
index 0095764747..4a1cf68b3d 100644
--- a/src/Mod/Sketcher/App/Sketch.cpp
+++ b/src/Mod/Sketcher/App/Sketch.cpp
@@ -3506,7 +3506,30 @@ bool Sketch::updateNonDrivingConstraints()
             }
             else if((*it).constr->Type==Diameter && (*it).constr->First>=0 ) {
 
-                (*it).constr->setValue(2.0**((*it).value));
+                // two cases, the geometry parameter is fixed or it is not
+                // NOTE: This is different from being blocked, as new block constraint may fix
+                // the parameter or not depending on whether other driving constraints are present
+                int geoId = (*it).constr->First;
+
+                geoId = checkGeoId( geoId );
+
+                double * rad = nullptr;
+
+                if (Geoms[geoId].type == Circle) {
+                    GCS::Circle &c = Circles[Geoms[geoId].index];
+                    rad = c.rad;
+                }
+                else if (Geoms[geoId].type == Arc) {
+                    GCS::Arc &a = Arcs[Geoms[geoId].index];
+                    rad = a.rad;
+                }
+
+                auto pos = std::find(FixParameters.begin(), FixParameters.end(), rad);
+
+                if (pos != FixParameters.end())
+                    (*it).constr->setValue(*((*it).value));
+                else
+                    (*it).constr->setValue(2.0**((*it).value));
             }
             else {
                 (*it).constr->setValue(*((*it).value));
diff --git a/src/Mod/Sketcher/App/planegcs/GCS.cpp b/src/Mod/Sketcher/App/planegcs/GCS.cpp
index 01e0f26ffd..68bc17d22a 100644
--- a/src/Mod/Sketcher/App/planegcs/GCS.cpp
+++ b/src/Mod/Sketcher/App/planegcs/GCS.cpp
@@ -1035,14 +1035,14 @@ int System::addConstraintArcRadius(Arc &a, double *radius, int tagId, bool drivi
     return addConstraintEqual(a.rad, radius, tagId, driving);
 }
 
-int System::addConstraintCircleDiameter(Circle &c, double *radius, int tagId, bool driving)
+int System::addConstraintCircleDiameter(Circle &c, double *diameter, int tagId, bool driving)
 {
-    return addConstraintProportional(c.rad, radius, 0.5, tagId, driving);
+    return addConstraintProportional(c.rad, diameter, 0.5, tagId, driving);
 }
 
-int System::addConstraintArcDiameter(Arc &a, double *radius, int tagId, bool driving)
+int System::addConstraintArcDiameter(Arc &a, double *diameter, int tagId, bool driving)
 {
-    return addConstraintProportional(a.rad, radius, 0.5, tagId, driving);
+    return addConstraintProportional(a.rad, diameter, 0.5, tagId, driving);
 }
 
 int System::addConstraintEqualLength(Line &l1, Line &l2, int tagId, bool driving)
diff --git a/src/Mod/Sketcher/App/planegcs/GCS.h b/src/Mod/Sketcher/App/planegcs/GCS.h
index ee606a5095..865bd238c0 100644
--- a/src/Mod/Sketcher/App/planegcs/GCS.h
+++ b/src/Mod/Sketcher/App/planegcs/GCS.h
@@ -295,8 +295,8 @@ namespace GCS
 
         int addConstraintCircleRadius(Circle &c, double *radius, int tagId=0, bool driving = true);
         int addConstraintArcRadius(Arc &a, double *radius, int tagId=0, bool driving = true);
-        int addConstraintCircleDiameter(Circle &c, double *radius, int tagId=0, bool driving = true);
-        int addConstraintArcDiameter(Arc &a, double *radius, int tagId=0, bool driving = true);
+        int addConstraintCircleDiameter(Circle &c, double *diameter, int tagId=0, bool driving = true);
+        int addConstraintArcDiameter(Arc &a, double *diameter, int tagId=0, bool driving = true);
         int addConstraintEqualLength(Line &l1, Line &l2, int tagId=0, bool driving = true);
         int addConstraintEqualRadius(Circle &c1, Circle &c2, int tagId=0, bool driving = true);
         int addConstraintEqualRadii(Ellipse &e1, Ellipse &e2, int tagId=0, bool driving = true);