From d0ddc909dc0c405785b25c106aa9f92116cb1301 Mon Sep 17 00:00:00 2001
From: Jeff Young <jeff@rokeby.ie>
Date: Mon, 19 Oct 2020 15:34:59 +0100
Subject: [PATCH] Handle hierarchical symbols when performing "lib symbol
 changed" check.

Fixes https://gitlab.com/kicad/code/kicad/issues/6002
---
 eeschema/erc.cpp | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/eeschema/erc.cpp b/eeschema/erc.cpp
index 330534be32..ec03c81930 100644
--- a/eeschema/erc.cpp
+++ b/eeschema/erc.cpp
@@ -632,15 +632,20 @@ int ERC_TESTER::TestLibSymbolIssues()
 
                 markers.emplace_back( new SCH_MARKER( ercItem, symbol->GetPosition() ) );
             }
-            else if( *libSymbol != *libSymbolInSchematic )
+            else
             {
-                std::shared_ptr<ERC_ITEM> ercItem = ERC_ITEM::Create( ERCE_LIB_SYMBOL_ISSUES );
-                ercItem->SetItems( symbol );
-                msg.Printf( "Library symbol \"%s\" has been modified",
-                            symbol->GetLibId().GetUniStringLibId() );
-                ercItem->SetErrorMessage( msg );
+                std::unique_ptr<LIB_PART> flattenedSymbol = libSymbol->Flatten();
 
-                markers.emplace_back( new SCH_MARKER( ercItem, symbol->GetPosition() ) );
+                if( *flattenedSymbol != *libSymbolInSchematic )
+                {
+                    std::shared_ptr<ERC_ITEM> ercItem = ERC_ITEM::Create( ERCE_LIB_SYMBOL_ISSUES );
+                    ercItem->SetItems( symbol );
+                    msg.Printf( "Library symbol \"%s\" has been modified",
+                                symbol->GetLibId().GetUniStringLibId() );
+                    ercItem->SetErrorMessage( msg );
+
+                    markers.emplace_back( new SCH_MARKER( ercItem, symbol->GetPosition() ) );
+                }
             }
         }