Fix highlighting complex connections from subsheets

Sheet() can't be used for local sheet recall in these cases

Fixes https://gitlab.com/kicad/code/kicad/-/issues/9403

eeschema/sch_connection.cpp

@@ -63,6 +63,7 @@
 
 SCH_CONNECTION::SCH_CONNECTION( SCH_ITEM* aParent, SCH_SHEET_PATH aPath ) :
         m_sheet( aPath ),
+        m_local_sheet( aPath ),
         m_parent( aParent ),
         m_driver( nullptr ),
         m_graph( nullptr )
@@ -73,6 +74,7 @@ SCH_CONNECTION::SCH_CONNECTION( SCH_ITEM* aParent, SCH_SHEET_PATH aPath ) :
 
 SCH_CONNECTION::SCH_CONNECTION( CONNECTION_GRAPH* aGraph ) :
         m_sheet( SCH_SHEET_PATH() ),
+        m_local_sheet( SCH_SHEET_PATH() ),
         m_parent( nullptr ),
         m_driver( nullptr ),
         m_graph( aGraph )
@@ -109,7 +111,8 @@ void SCH_CONNECTION::SetDriver( SCH_ITEM* aItem )
 
 void SCH_CONNECTION::SetSheet( SCH_SHEET_PATH aSheet )
 {
-    m_sheet = aSheet;
+    m_sheet       = aSheet;
+    m_local_sheet = aSheet;
 
     recacheName();
 
@@ -230,6 +233,7 @@ void SCH_CONNECTION::Clone( const SCH_CONNECTION& aOther )
     // Note: m_lastDriver is not cloned as it needs to be the last driver of *this* connection
     m_driver = aOther.Driver();
     m_sheet  = aOther.Sheet();
+    // Note: m_local_sheet is not cloned
     m_name   = aOther.m_name;
     // Note: m_local_name is not cloned if not set yet
     if( m_local_name.IsEmpty() )

eeschema/sch_connection.h

@@ -109,6 +109,8 @@ public:
     SCH_SHEET_PATH Sheet() const { return m_sheet; }
     void SetSheet( SCH_SHEET_PATH aSheet );
 
+    SCH_SHEET_PATH LocalSheet() const { return m_local_sheet; }
+
     /**
      * Checks if the SCH_ITEM this connection is attached to can drive connections
      * Drivers can be labels, sheet pins, or symbol pins.
@@ -240,6 +242,14 @@ private:
 
     SCH_SHEET_PATH m_sheet; ///< The hierarchical sheet this connection is on
 
+    /**
+     * When a connection is overridden by one on a different hierarchical sheet, it will be cloned
+     * and m_sheet will point to the parent sheet.  This member stores the original sheet so that it
+     * can be used for applications such as net highlighting to retrieve the sheet of the parent
+     * item from the highlighted connection.
+     */
+    SCH_SHEET_PATH m_local_sheet;
+
     SCH_ITEM* m_parent;     ///< The SCH_ITEM this connection is owned by
 
     void*     m_lastDriver; ///< WEAK POINTER (there is no guarantee it is still allocated)

eeschema/sch_edit_frame.cpp

@@ -1285,7 +1285,7 @@ void SCH_EDIT_FRAME::RecalculateConnections( SCH_CLEANUP_FLAGS aCleanupFlags )
     SCH_SHEET_PATH highlightPath;
 
     if( highlight )
-        highlightPath = highlight->Sheet();
+        highlightPath = highlight->LocalSheet();
 
     SCHEMATIC_SETTINGS& settings = Schematic().Settings();
     SCH_SHEET_LIST      list = Schematic().GetSheets();