Fix crash on save after pasting symbols in schematic editor.

This was caused by pasting zero length instance paths which are not valid.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/16300

eeschema/tools/sch_editor_control.cpp

@@ -1387,21 +1387,19 @@ void SCH_EDITOR_CONTROL::updatePastedSymbol( SCH_SYMBOL* aSymbol, SCH_SCREEN* aP
                                              const KIID_PATH& aClipPath,
                                              bool aForceKeepAnnotations )
 {
-    wxCHECK( aSymbol && aPasteScreen, /* void */ );
+    wxCHECK( m_frame && aSymbol && aPasteScreen, /* void */ );
 
-    KIID_PATH clipItemPath = aClipPath;
+    SCH_SYMBOL_INSTANCE instance;
+    KIID_PATH pasteLookupPath = aClipPath;
 
-    wxString reference, value, footprint;
-    int      unit;
+    m_pastedSymbols.insert( aSymbol );
 
-    clipItemPath.push_back( aSymbol->m_Uuid );
+    // The pasted symbol look up paths include the symbol UUID.
+    pasteLookupPath.push_back( aSymbol->m_Uuid );
 
-    if( m_clipboardSymbolInstances.count( clipItemPath ) > 0 )
+    if( m_clipboardSymbolInstances.count( pasteLookupPath ) > 0 )
     {
-        SCH_SYMBOL_INSTANCE instance = m_clipboardSymbolInstances.at( clipItemPath );
-
-        unit = instance.m_Unit;
-        reference = instance.m_Reference;
+        instance = m_clipboardSymbolInstances.at( pasteLookupPath );
     }
     else
     {
@@ -1412,20 +1410,20 @@ void SCH_EDITOR_CONTROL::updatePastedSymbol( SCH_SYMBOL* aSymbol, SCH_SCREEN* aP
 
         // Pasted from notepad or an older instance of eeschema.  Use the values in the fields
         // instead.
-        reference = aSymbol->GetField( REFERENCE_FIELD )->GetText();
-        value = aSymbol->GetField( VALUE_FIELD )->GetText();
-        footprint = aSymbol->GetField( FOOTPRINT_FIELD )->GetText();
-        unit = aSymbol->GetUnit();
+        instance.m_Reference = aSymbol->GetField( REFERENCE_FIELD )->GetText();
+        instance.m_Unit = aSymbol->GetUnit();
     }
 
-    if( aForceKeepAnnotations && !reference.IsEmpty() )
-        aSymbol->SetRef( &aPastePath, reference );
-    else
+    instance.m_Path = aPastePath.Path() + aClipPath;
+    instance.m_ProjectName = m_frame->Prj().GetProjectName();
+
+    aSymbol->AddHierarchicalReference( instance );
+
+    if( !aForceKeepAnnotations )
         aSymbol->ClearAnnotation( &aPastePath, false );
 
     // We might clear annotations but always leave the original unit number from the paste.
-    aSymbol->SetUnitSelection( &aPastePath, unit );
-    aSymbol->SetUnit( unit );
+    aSymbol->SetUnit( instance.m_Unit );
 }
 
 
@@ -1531,6 +1529,29 @@ void SCH_EDITOR_CONTROL::setPastedSymbolInstances( SCH_SCREENS& aScreenList )
 }
 
 
+void SCH_EDITOR_CONTROL::prunePastedSymbolInstances()
+{
+    wxCHECK( m_frame, /* void */ );
+
+    for( SCH_SYMBOL* symbol : m_pastedSymbols )
+    {
+        wxCHECK2( symbol, continue );
+
+        std::vector<KIID_PATH> instancePathsToRemove;
+
+        for( const SCH_SYMBOL_INSTANCE& instance : symbol->GetInstanceReferences() )
+        {
+            if( ( instance.m_ProjectName != m_frame->Prj().GetProjectName() )
+              || instance.m_Path.empty() )
+                instancePathsToRemove.emplace_back( instance.m_Path );
+        }
+
+        for( const KIID_PATH& path : instancePathsToRemove )
+            symbol->RemoveInstance( path );
+    }
+}
+
+
 int SCH_EDITOR_CONTROL::Paste( const TOOL_EVENT& aEvent )
 {
     wxTextEntry* textEntry = dynamic_cast<wxTextEntry*>( wxWindow::FindFocus() );
@@ -1581,6 +1602,7 @@ int SCH_EDITOR_CONTROL::Paste( const TOOL_EVENT& aEvent )
 
     SCH_SCREENS tempScreens( tempSheet );
 
+    m_pastedSymbols.clear();
     m_clipboardSheetInstances.clear();
     m_clipboardSymbolInstances.clear();
 
@@ -1934,6 +1956,8 @@ int SCH_EDITOR_CONTROL::Paste( const TOOL_EVENT& aEvent )
 
     m_frame->GetCurrentSheet().UpdateAllScreenReferences();
 
+    prunePastedSymbolInstances();
+
     // The copy operation creates instance paths that are not valid for the current project or
     // saved as part of another project.  Prune them now so they do not accumulate in the saved
     // schematic file.

eeschema/tools/sch_editor_control.h

@@ -194,6 +194,16 @@ private:
     void setPastedSheetInstances( const SCH_SHEET* aPastedSheet );
     void setPastedSymbolInstances( SCH_SCREENS& aScreenList );
 
+    /**
+     * Remove all pasted symbol instances that do not belong to the current project.
+     *
+     * @warning This should **only** be called when cleaning up after a paste.  Otherwise it
+     *          could clobber symbol instances for schematics shared across projects.  Use
+     *          SCH_SCREENS::PruneOrphanedSymbolInstances() to clean up invalid instance for
+     *          the current project.
+     */
+    void prunePastedSymbolInstances();
+
     /**
      * Read the footprint info from each line in the stuff file by reference designator.
      *
@@ -238,6 +248,8 @@ private:
 
     // A map of KIID_PATH --> sheet instances for the clipboard contents.
     std::map<KIID_PATH, SCH_SHEET_INSTANCE>  m_clipboardSheetInstances;
+
+    std::set<SCH_SYMBOL*>                    m_pastedSymbols;
 };
 
 

include/kiid.h

@@ -3,7 +3,7 @@
  *
  * Copyright (C) 2020 Ian McInerney <ian.s.mcinerney@ieee.org>
  * Copyright (C) 2007-2014 Jean-Pierre Charras, jp.charras at wanadoo.fr
- * Copyright (C) 1992-2022 KiCad Developers, see AUTHORS.TXT for contributors.
+ * Copyright (C) 1992-2023 KiCad Developers, see AUTHORS.TXT for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -191,6 +191,20 @@ public:
 
         return false;
     }
+
+    KIID_PATH& operator+=( const KIID_PATH& aRhs )
+    {
+        for( const KIID& kiid : aRhs )
+            emplace_back( kiid );
+
+        return *this;
+    }
+
+    friend KIID_PATH operator+( KIID_PATH aLhs, const KIID_PATH& aRhs )
+    {
+        aLhs += aRhs;
+        return aLhs;
+    }
 };
 
 /**