From 356faf94da63f9c2c92583bfe347f5616d61c52b Mon Sep 17 00:00:00 2001
From: wandererfan <wandererfan@gmail.com>
Date: Mon, 14 Nov 2022 16:03:21 -0500
Subject: [PATCH] [TD]prevent Complex Section with no Base View

---
 src/Mod/TechDraw/App/DrawViewSection.cpp    | 12 ++++++-----
 src/Mod/TechDraw/Gui/Command.cpp            |  6 ++++++
 src/Mod/TechDraw/Gui/TaskComplexSection.cpp | 22 ++++++++++++++-------
 3 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/src/Mod/TechDraw/App/DrawViewSection.cpp b/src/Mod/TechDraw/App/DrawViewSection.cpp
index d2224bfd19..8f481fc55a 100644
--- a/src/Mod/TechDraw/App/DrawViewSection.cpp
+++ b/src/Mod/TechDraw/App/DrawViewSection.cpp
@@ -801,11 +801,13 @@ Base::Vector3d DrawViewSection::getXDirection() const
         //we have an XDirection property
         if (DrawUtil::fpCompare(XDirection.getValue().Length(), 0.0)) {
             //but it has no value, so we make a value
-            gp_Ax2 cs = getCSFromBase(SectionDirection.getValueAsString());
-            gp_Dir gXDir = cs.XDirection();
-            result = Base::Vector3d(gXDir.X(),
-                                    gXDir.Y(),
-                                    gXDir.Z());
+            if (BaseView.getValue()) {
+                gp_Ax2 cs = getCSFromBase(SectionDirection.getValueAsString());
+                gp_Dir gXDir = cs.XDirection();
+                result = Base::Vector3d(gXDir.X(),
+                                        gXDir.Y(),
+                                        gXDir.Z());
+            }
         } else {
             //XDirection is good, so we use it
             result = XDirection.getValue();
diff --git a/src/Mod/TechDraw/Gui/Command.cpp b/src/Mod/TechDraw/Gui/Command.cpp
index 52947210ed..3185eb93fc 100644
--- a/src/Mod/TechDraw/Gui/Command.cpp
+++ b/src/Mod/TechDraw/Gui/Command.cpp
@@ -737,6 +737,12 @@ void execComplexSection(Gui::Command* cmd)
         }
     }
 
+    if (!baseView) {
+        QMessageBox::warning(Gui::getMainWindow(), QObject::tr("Wrong selection"),
+            QObject::tr("I do not know what base view to use."));
+        return;
+    }
+
     if (shapes.empty() &&
         xShapes.empty() &&
         !baseView) {
diff --git a/src/Mod/TechDraw/Gui/TaskComplexSection.cpp b/src/Mod/TechDraw/Gui/TaskComplexSection.cpp
index b241a9d80d..d8cf2f37e8 100644
--- a/src/Mod/TechDraw/Gui/TaskComplexSection.cpp
+++ b/src/Mod/TechDraw/Gui/TaskComplexSection.cpp
@@ -91,11 +91,13 @@ TaskComplexSection::TaskComplexSection(TechDraw::DrawPage* page,
     m_directionIsSet(false)
 {
     m_sectionName = std::string();
-    m_doc         = m_baseView->getDocument();
-
-    m_saveBaseName = m_baseView->getNameInDocument();
-    m_savePageName = m_baseView->findParentPage()->getNameInDocument();
-
+    if (m_page) {
+        m_doc = m_page->getDocument();
+        m_savePageName = m_page->getNameInDocument();
+    }
+    if (m_baseView) {
+        m_saveBaseName = m_baseView->getNameInDocument();
+    }
     ui->setupUi(this);
 
     saveSectionState();
@@ -120,11 +122,14 @@ TaskComplexSection::TaskComplexSection(TechDraw::DrawComplexSection* complexSect
 {
     m_sectionName = m_section->getNameInDocument();
     m_doc         = m_section->getDocument();
+    m_page        = m_section->findParentPage();
+    m_savePageName = m_page->getNameInDocument();
+
     m_baseView = dynamic_cast<TechDraw::DrawViewPart*> (m_section->BaseView.getValue());
     if (m_baseView) {
         m_saveBaseName = m_baseView->getNameInDocument();
-        m_savePageName = m_baseView->findParentPage()->getNameInDocument();
     }
+
     m_shapes = m_section->Source.getValues();
     m_xShapes = m_section->XSource.getValues();
     m_profileObject = m_section->CuttingToolWireObject.getValue();
@@ -305,7 +310,10 @@ void TaskComplexSection::slotViewDirectionChanged(Base::Vector3d newDirection)
 {
 //    Base::Console().Message("TCS::slotViewDirectionChanged(%s)\n",
 //                            DrawUtil::formatVector(newDirection).c_str());
-    Base::Vector3d projectedViewDirection = m_baseView->projectPoint(newDirection, false);
+    Base::Vector3d projectedViewDirection = newDirection;
+    if (m_baseView) {
+        projectedViewDirection = m_baseView->projectPoint(newDirection, false);
+    }
     projectedViewDirection.Normalize();
     double viewAngle = atan2(projectedViewDirection.y,
                              projectedViewDirection.x);