From 3e9eb3c8acab5131341f9452988a959387cb376c Mon Sep 17 00:00:00 2001
From: Jeff Young <jeff@rokeby.ie>
Date: Fri, 5 Mar 2021 15:30:12 +0000
Subject: [PATCH] More complete fix for crasher JP found.

Fixes https://gitlab.com/kicad/code/kicad/issues/7806
---
 include/board_design_settings.h  | 32 ++---------------
 pcbnew/board_design_settings.cpp | 60 ++++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+), 29 deletions(-)

diff --git a/include/board_design_settings.h b/include/board_design_settings.h
index 8ca74f6d72..98c32233ca 100644
--- a/include/board_design_settings.h
+++ b/include/board_design_settings.h
@@ -541,47 +541,21 @@ public:
     /**
      * @return the current diff pair track width, according to the selected options
      * ( using the default netclass value or a preset/custom value )
-     * the default netclass is always in m_DiffPairDimensionsList[0].
      */
-    inline int GetCurrentDiffPairWidth() const
-    {
-        if( m_useCustomDiffPair )
-            return m_customDiffPair.m_Width;
-        else if( m_diffPairIndex < m_DiffPairDimensionsList.size() )
-            return m_DiffPairDimensionsList[m_diffPairIndex].m_Width;
-        else
-            return GetCurrentTrackWidth();
-    }
+    int GetCurrentDiffPairWidth() const;
 
     /**
      * @return the current diff pair gap, according to the selected options
      * ( using the default netclass value or a preset/custom value )
-     * the default netclass is always in m_DiffPairDimensionsList[0].
      */
-    inline int GetCurrentDiffPairGap() const
-    {
-        if( m_useCustomDiffPair )
-            return m_customDiffPair.m_Gap;
-        else if( m_diffPairIndex < m_DiffPairDimensionsList.size() )
-            return m_DiffPairDimensionsList[m_diffPairIndex].m_Gap;
-        else
-            return GetSmallestClearanceValue();
-    }
+    int GetCurrentDiffPairGap() const;
 
     /**
      * @return the current diff pair via gap, according to the selected options
      * ( using the default netclass value or a preset/custom value )
      * the default netclass is always in m_DiffPairDimensionsList[0].
      */
-    inline int GetCurrentDiffPairViaGap() const
-    {
-        if( m_useCustomDiffPair )
-            return m_customDiffPair.m_ViaGap;
-        else if( m_diffPairIndex < m_DiffPairDimensionsList.size() )
-            return m_DiffPairDimensionsList[m_diffPairIndex].m_ViaGap;
-        else
-            return GetSmallestClearanceValue();
-    }
+    int GetCurrentDiffPairViaGap() const;
 
     /**
      * @param aValue The minimum distance between the edges of two holes or 0 to disable
diff --git a/pcbnew/board_design_settings.cpp b/pcbnew/board_design_settings.cpp
index 2265db8fab..a88f22e366 100644
--- a/pcbnew/board_design_settings.cpp
+++ b/pcbnew/board_design_settings.cpp
@@ -974,6 +974,66 @@ void BOARD_DESIGN_SETTINGS::SetDiffPairIndex( unsigned aIndex )
 }
 
 
+int BOARD_DESIGN_SETTINGS::GetCurrentDiffPairWidth() const
+{
+    if( m_useCustomDiffPair )
+    {
+        return m_customDiffPair.m_Width;
+    }
+    else if( m_diffPairIndex == 0 )
+    {
+        if( GetNetClasses().GetDefaultPtr()->HasDiffPairWidth() )
+            return GetNetClasses().GetDefaultPtr()->GetDiffPairWidth();
+        else
+            return GetNetClasses().GetDefaultPtr()->GetTrackWidth();
+    }
+    else
+    {
+        return m_DiffPairDimensionsList[m_diffPairIndex].m_Width;
+    }
+}
+
+
+int BOARD_DESIGN_SETTINGS::GetCurrentDiffPairGap() const
+{
+    if( m_useCustomDiffPair )
+    {
+        return m_customDiffPair.m_Gap;
+    }
+    else if( m_diffPairIndex == 0 )
+    {
+        if( GetNetClasses().GetDefaultPtr()->HasDiffPairGap() )
+            return GetNetClasses().GetDefaultPtr()->GetDiffPairGap();
+        else
+            return GetNetClasses().GetDefaultPtr()->GetClearance();
+    }
+    else
+    {
+        return m_DiffPairDimensionsList[m_diffPairIndex].m_Gap;
+    }
+}
+
+
+int BOARD_DESIGN_SETTINGS::GetCurrentDiffPairViaGap() const
+{
+    if( m_useCustomDiffPair )
+    {
+        return m_customDiffPair.m_ViaGap;
+    }
+    else if( m_diffPairIndex == 0 )
+    {
+        if( GetNetClasses().GetDefaultPtr()->HasDiffPairViaGap() )
+            return GetNetClasses().GetDefaultPtr()->GetDiffPairViaGap();
+        else
+            return GetCurrentDiffPairGap();
+    }
+    else
+    {
+        return m_DiffPairDimensionsList[m_diffPairIndex].m_ViaGap;
+    }
+}
+
+
 void BOARD_DESIGN_SETTINGS::SetMinHoleSeparation( int aDistance )
 {
     m_HoleToHoleMin = aDistance;