Remove duplicate references from change symbol dialog.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/15480

eeschema/dialogs/dialog_change_symbols.cpp

@@ -723,8 +723,18 @@ wxString DIALOG_CHANGE_SYMBOLS::getSymbolReferences( SCH_SYMBOL& aSymbol, const
     wxString references;
     LIB_ID oldId = aSymbol.GetLibId();
 
+    SCH_EDIT_FRAME* parent = dynamic_cast< SCH_EDIT_FRAME* >( GetParent() );
+
+    wxCHECK( parent, msg );
+
+    SCH_SHEET_LIST sheets = parent->Schematic().GetSheets();
+
     for( const SCH_SYMBOL_INSTANCE& instance : aSymbol.GetInstanceReferences() )
     {
+        // Only include the symbol instances for the current project.
+        if( !sheets.HasPath( instance.m_Path ) )
+            continue;
+
         if( references.IsEmpty() )
             references = instance.m_Reference;
         else

eeschema/sch_sheet_path.cpp

@@ -1306,3 +1306,14 @@ int SCH_SHEET_LIST::GetLastVirtualPageNumber() const
     return lastVirtualPageNumber;
 }
 
+
+bool SCH_SHEET_LIST::HasPath( const KIID_PATH& aPath ) const
+{
+    for( const SCH_SHEET_PATH& path : *this )
+    {
+        if( path.Path() == aPath )
+            return true;
+    }
+
+    return false;
+}

eeschema/sch_sheet_path.h

@@ -672,6 +672,8 @@ public:
 
     void RemoveSymbolInstances( const SCH_SHEET_PATH& aPrefixSheetPath );
 
+    bool HasPath( const KIID_PATH& aPath ) const;
+
 private:
     SCH_SHEET_PATH  m_currentSheetPath;
 };