Special-case net-ties for solder mask bridging.

Fixes https://gitlab.com/kicad/code/kicad/issues/13646

pcbnew/drc/drc_test_provider_solder_mask.cpp

@@ -441,7 +441,8 @@ void DRC_TEST_PROVIDER_SOLDER_MASK::testItemAgainstItems( BOARD_ITEM* aItem, con
                         return false;
                 }
 
-                if( pad && otherPad && pad->SameLogicalPadAs( otherPad ) )
+                if( pad && otherPad && ( pad->SameLogicalPadAs( otherPad )
+                                         || pad->SharesNetTieGroup( otherPad ) ) )
                 {
                     return false;
                 }

pcbnew/pad.cpp

@@ -162,6 +162,23 @@ bool PAD::IsLocked() const
 };
 
 
+bool PAD::SharesNetTieGroup( const PAD* aOther ) const
+{
+    FOOTPRINT* parentFp = static_cast<FOOTPRINT*>( GetParentFootprint() );
+
+    if( parentFp && parentFp->IsNetTie() && aOther->GetParentFootprint() == parentFp )
+    {
+        std::map<wxString, int> padToNetTieGroupMap = parentFp->MapPadNumbersToNetTieGroups();
+        int thisNetTieGroup = padToNetTieGroupMap[ GetNumber() ];
+        int otherNetTieGroup = padToNetTieGroupMap[ aOther->GetNumber() ];
+
+        return thisNetTieGroup >= 0 && thisNetTieGroup == otherNetTieGroup;
+    }
+
+    return false;
+}
+
+
 bool PAD::IsNoConnectPad() const
 {
     return GetShortNetname().StartsWith( wxT( "unconnected-(" ) )

pcbnew/pad.h

@@ -155,13 +155,18 @@ public:
      * Before we had custom pad shapes it was common to have multiple overlapping pads to
      * represent a more complex shape.
      */
-    bool SameLogicalPadAs( const PAD* other ) const
+    bool SameLogicalPadAs( const PAD* aOther ) const
     {
         // hide tricks behind sensible API
-        return GetParentFootprint() == other->GetParentFootprint()
-            && !m_number.IsEmpty() && m_number == other->m_number;
+        return GetParentFootprint() == aOther->GetParentFootprint()
+            && !m_number.IsEmpty() && m_number == aOther->m_number;
     }
 
+    /**
+     * @return true if this and \aOther represent a net-tie.
+     */
+    bool SharesNetTieGroup( const PAD* aOther ) const;
+
     /**
      * @return true if the pad is associated with an "unconnected" pin (or a no-connect symbol)
      * and has no net.