From 101040c395e37816e8ab007a58d24cab035e1b60 Mon Sep 17 00:00:00 2001
From: Ajinkya Dahale <AjinkyaDahale@users.noreply.github.com>
Date: Thu, 3 Oct 2024 22:00:22 +0530
Subject: [PATCH] [Sketcher] Apply tangent autoconstraint only when `Dir` given

This relates to `seekAutoConstraint` and `seekAndRenderAutoConstraint`.

Fixes #16321.
---
 src/Mod/Sketcher/Gui/DrawSketchHandler.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/Mod/Sketcher/Gui/DrawSketchHandler.cpp b/src/Mod/Sketcher/Gui/DrawSketchHandler.cpp
index a8383e8a90..93f2074858 100644
--- a/src/Mod/Sketcher/Gui/DrawSketchHandler.cpp
+++ b/src/Mod/Sketcher/Gui/DrawSketchHandler.cpp
@@ -511,9 +511,12 @@ int DrawSketchHandler::seekAutoConstraint(std::vector<AutoConstraint>& suggested
             constr.Type = Sketcher::Tangent;
         }
 
-        if (constr.Type == Sketcher::Tangent && Dir.Length() > 1e-8
-            && hitShapeDir.Length()
-                > 1e-8) {  // We are hitting a line and have hitting vector information
+        if (constr.Type == Sketcher::Tangent) {
+            if (Dir.Length() < 1e-8 || hitShapeDir.Length() < 1e-8) {
+                // Direction not set so return;
+                return suggestedConstraints.size();
+            }
+            // We are hitting a line and have hitting vector information
             Base::Vector3d dir3d = Base::Vector3d(Dir.x, Dir.y, 0);
             double cosangle = dir3d.Normalize() * hitShapeDir.Normalize();