Footprint editor: ensure the pad editor is closed before load a new footprint.

When editing a new footprint from the board editor, if the Footprint editor has the pad editor
open, there is a risk of crash when replacing the footprint in edit.

Fixes #6892
https://gitlab.com/kicad/code/kicad/issues/6892

pcbnew/dialogs/dialog_pad_properties.cpp

@@ -135,6 +135,8 @@ DIALOG_PAD_PROPERTIES::DIALOG_PAD_PROPERTIES( PCB_BASE_FRAME* aParent, PAD* aPad
     m_spokeWidth( aParent, m_spokeWidthLabel, m_spokeWidthCtrl, m_spokeWidthUnits, true ),
     m_thermalGap( aParent, m_thermalGapLabel, m_thermalGapCtrl, m_thermalGapUnits, true )
 {
+    SetName( PAD_PROPERTIES_DLG_NAME );
+
     m_currentPad = aPad;        // aPad can be NULL, if the dialog is called
                                 // from the footprint editor to set default pad setup
 

pcbnew/dialogs/dialog_pad_properties.h

@@ -44,6 +44,9 @@
  * DIALOG_PAD_PROPERTIES, derived from DIALOG_PAD_PROPERTIES_BASE,
  * created by wxFormBuilder
  */
+// The wxWidgets window name. Used to retrieve the dialog by window name
+#define PAD_PROPERTIES_DLG_NAME "pad_properties_dlg_name"
+
 class DIALOG_PAD_PROPERTIES : public DIALOG_PAD_PROPERTIES_BASE
 {
 public:

pcbnew/load_select_footprint.cpp

@@ -51,6 +51,7 @@ using namespace std::placeholders;
 #include <view/view_controls.h>
 #include <widgets/lib_tree.h>
 #include <widgets/progress_reporter.h>
+#include <dialog_pad_properties.h>
 
 #include "fp_tree_model_adapter.h"
 
@@ -98,6 +99,12 @@ bool FOOTPRINT_EDIT_FRAME::LoadFootprintFromBoard( FOOTPRINT* aFootprint )
     if( aFootprint == NULL )
         return false;
 
+    // Ensure we do not have the pad editor open (that is apseudo modal dlg).
+    // LoadFootprintFromBoard() can be called from the board editor, and we must ensure
+    // no footprint item is currently in edit
+    if( wxWindow::FindWindowByName( PAD_PROPERTIES_DLG_NAME ) )
+        wxWindow::FindWindowByName( PAD_PROPERTIES_DLG_NAME )->Close();
+
     if( !Clear_Pcb( true ) )
         return false;