Fix pad snapping in renumber pads

Snap shouldn't be looking for other items in this routine or using the
grid

Fixes https://gitlab.com/kicad/code/kicad/issues/10238

(cherry picked from commit ed9a3deb57)

pcbnew/tools/pad_tool.cpp

@@ -32,9 +32,11 @@
 #include <footprint.h>
 #include <fp_shape.h>
 #include <pad.h>
+#include <pcbnew_settings.h>
 #include <board_commit.h>
 #include <dialogs/dialog_push_pad_properties.h>
 #include <tools/pcb_actions.h>
+#include <tools/pcb_grid_helper.h>
 #include <tools/pcb_selection_tool.h>
 #include <tools/pcb_selection_conditions.h>
 #include <tools/edit_tool.h>
@@ -295,6 +297,16 @@ int PAD_TOOL::EnumeratePads( const TOOL_EVENT& aEvent )
     std::list<PAD*> selectedPads;
     BOARD_COMMIT    commit( frame() );
     bool            isFirstPoint = true;   // make sure oldCursorPos is initialized at least once
+    PADS            pads = board()->GetFirstFootprint()->Pads();
+
+    MAGNETIC_SETTINGS mag_settings;
+    mag_settings.graphics = false;
+    mag_settings.tracks = MAGNETIC_OPTIONS::NO_EFFECT;
+    mag_settings.pads = MAGNETIC_OPTIONS::CAPTURE_ALWAYS;
+    PCB_GRID_HELPER grid( m_toolMgr, &mag_settings );
+
+    grid.SetSnap( true );
+    grid.SetUseGrid( false );
 
     auto setCursor =
             [&]()
@@ -318,6 +330,9 @@ int PAD_TOOL::EnumeratePads( const TOOL_EVENT& aEvent )
     {
         setCursor();
 
+        VECTOR2I cursorPos = grid.AlignToNearestPad( getViewControls()->GetMousePosition(), pads );
+        getViewControls()->ForceCursorPosition( true, cursorPos );
+
         if( evt->IsCancelInteractive() )
         {
             m_toolMgr->RunAction( PCB_ACTIONS::selectionClear, true );
@@ -336,7 +351,6 @@ int PAD_TOOL::EnumeratePads( const TOOL_EVENT& aEvent )
         else if( evt->IsDrag( BUT_LEFT ) || evt->IsClick( BUT_LEFT ) )
         {
             selectedPads.clear();
-            VECTOR2I cursorPos = getViewControls()->GetCursorPosition();
 
             // Be sure the old cursor mouse position was initialized:
             if( isFirstPoint )

pcbnew/tools/pcb_grid_helper.cpp

@@ -151,6 +151,39 @@ VECTOR2I PCB_GRID_HELPER::AlignToArc( const VECTOR2I& aPoint, const SHAPE_ARC& a
 }
 
 
+VECTOR2I PCB_GRID_HELPER::AlignToNearestPad( const VECTOR2I& aMousePos, PADS& aPads )
+{
+    clearAnchors();
+
+    for( BOARD_ITEM* item : aPads )
+        computeAnchors( item, aMousePos, true );
+
+    double  minDist = std::numeric_limits<double>::max();
+    ANCHOR* nearestOrigin = nullptr;
+
+    for( ANCHOR& a : m_anchors )
+    {
+        BOARD_ITEM* item = static_cast<BOARD_ITEM*>( a.item );
+
+        if( ( ORIGIN & a.flags ) != ORIGIN )
+            continue;
+
+        if( !item->HitTest( aMousePos ) )
+            continue;
+
+        double dist = a.Distance( aMousePos );
+
+        if( dist < minDist )
+        {
+            minDist = dist;
+            nearestOrigin = &a;
+        }
+    }
+
+    return nearestOrigin ? nearestOrigin->pos : aMousePos;
+}
+
+
 VECTOR2I PCB_GRID_HELPER::BestDragOrigin( const VECTOR2I &aMousePos,
                                           std::vector<BOARD_ITEM*>& aItems )
 {

pcbnew/tools/pcb_grid_helper.h

@@ -27,6 +27,7 @@
 #define PCB_GRID_HELPER_H
 
 #include <vector>
+#include <pcb_item_containers.h>
 #include <tool/grid_helper.h>
 
 class TOOL_MANAGER;
@@ -52,6 +53,8 @@ public:
 
     VECTOR2I AlignToArc ( const VECTOR2I& aPoint, const SHAPE_ARC& aSeg );
 
+    VECTOR2I AlignToNearestPad( const VECTOR2I& aMousePos, PADS& aPads );
+
     /**
      * Chooses the "best" snap anchor around the given point, optionally taking layers from
      * the reference item.  The reference item will not be snapped to (it is being dragged or