Clear Scintilla undo history after setting initial text.

Fixes https://gitlab.com/kicad/code/kicad/issues/12650

eeschema/dialogs/dialog_field_properties.cpp

@@ -302,9 +302,14 @@ void DIALOG_FIELD_PROPERTIES::onVAlignButton( wxCommandEvent& aEvent )
 bool DIALOG_FIELD_PROPERTIES::TransferDataToWindow()
 {
     if( m_TextCtrl->IsShown() )
+    {
         m_TextCtrl->SetValue( m_text );
+    }
     else if( m_StyledTextCtrl->IsShown() )
+    {
         m_StyledTextCtrl->SetValue( m_text );
+        m_StyledTextCtrl->EmptyUndoBuffer();
+    }
 
     m_fontCtrl->SetFontSelection( m_font );
 

eeschema/dialogs/dialog_lib_text_properties.cpp

@@ -126,6 +126,7 @@ bool DIALOG_LIB_TEXT_PROPERTIES::TransferDataToWindow()
     {
         m_textSize.SetValue( m_graphicText->GetTextWidth() );
         m_StyledTextCtrl->SetValue( m_graphicText->GetText() );
+        m_StyledTextCtrl->EmptyUndoBuffer();
 
         m_fontCtrl->SetFontSelection( m_graphicText->GetFont() );
         m_textColorSwatch->SetSwatchColor( m_graphicText->GetTextColor(), false );

eeschema/dialogs/dialog_lib_textbox_properties.cpp

@@ -142,6 +142,7 @@ bool DIALOG_LIB_TEXTBOX_PROPERTIES::TransferDataToWindow()
         return false;
 
     m_textCtrl->SetValue( m_currentText->GetText() );
+    m_textCtrl->EmptyUndoBuffer();
 
     m_fontCtrl->SetFontSelection( m_currentText->GetFont() );
     m_textSize.SetValue( m_currentText->GetTextWidth() );

eeschema/dialogs/dialog_text_properties.cpp

@@ -205,6 +205,7 @@ bool DIALOG_TEXT_PROPERTIES::TransferDataToWindow()
 
     // show text variable cross-references in a human-readable format
     m_textCtrl->SetValue( schematic.ConvertKIIDsToRefs( m_currentText->GetText() ) );
+    m_textCtrl->EmptyUndoBuffer();
 
     m_fontCtrl->SetFontSelection( m_currentText->GetFont() );
     m_textSize.SetValue( m_currentText->GetTextWidth() );

pagelayout_editor/dialogs/properties_frame.cpp

@@ -259,6 +259,7 @@ void PROPERTIES_FRAME::CopyPrmsFromItemToPanel( DS_DATA_ITEM* aItem )
         // Replace our '\' 'n' sequence by the EOL char
         item->ReplaceAntiSlashSequence();
         m_stcText->SetValue( item->m_FullText );
+        m_stcText->EmptyUndoBuffer();
 
         msg.Printf( wxT( "%d" ), item->m_IncrementLabel );
         m_textCtrlTextIncrement->SetValue( msg );

pcbnew/dialogs/dialog_text_properties.cpp

@@ -233,6 +233,7 @@ bool DIALOG_TEXT_PROPERTIES::TransferDataToWindow()
 
         m_MultiLineText->SetValue( converted );
         m_MultiLineText->SetSelection( -1, -1 );
+        m_MultiLineText->EmptyUndoBuffer();
     }
 
     if( m_item->Type() == PCB_FP_TEXT_T && m_fpText )

pcbnew/dialogs/dialog_textbox_properties.cpp

@@ -169,6 +169,7 @@ bool DIALOG_TEXTBOX_PROPERTIES::TransferDataToWindow()
 
     m_MultiLineText->SetValue( converted );
     m_MultiLineText->SetSelection( -1, -1 );
+    m_MultiLineText->EmptyUndoBuffer();
 
     m_cbLocked->SetValue( m_item->IsLocked() );
 

pcbnew/dialogs/panel_setup_rules.cpp

@@ -594,6 +594,8 @@ bool PANEL_SETUP_RULES::TransferDataToWindow()
                 m_textEditor->AddText( str << '\n' );
             }
 
+            m_textEditor->EmptyUndoBuffer();
+
             wxCommandEvent dummy;
             OnCompile( dummy );
         }