Correctly format pad-to-die delays in sexpr format

common/eda_units.cpp

@@ -191,12 +191,13 @@ std::string EDA_UNIT_UTILS::FormatAngle( const EDA_ANGLE& aAngle )
 }
 
 
-std::string EDA_UNIT_UTILS::FormatInternalUnits( const EDA_IU_SCALE& aIuScale, int aValue )
+std::string EDA_UNIT_UTILS::FormatInternalUnits( const EDA_IU_SCALE& aIuScale, const int aValue,
+                                                 const EDA_DATA_TYPE aDataType )
 {
     std::string buf;
     double engUnits = aValue;
 
-    engUnits /= aIuScale.IU_PER_MM;
+    engUnits /= GetScaleForInternalUnitType( aIuScale, aDataType );
 
     if( engUnits != 0.0 && fabs( engUnits ) <= 0.0001 )
     {
@@ -232,6 +233,18 @@ std::string EDA_UNIT_UTILS::FormatInternalUnits( const EDA_IU_SCALE& aIuScale,
 }
 
 
+double EDA_UNIT_UTILS::GetScaleForInternalUnitType( const EDA_IU_SCALE& aIuScale, const EDA_DATA_TYPE aDataType )
+{
+    switch( aDataType )
+    {
+    case EDA_DATA_TYPE::TIME: return aIuScale.IU_PER_PS;
+    case EDA_DATA_TYPE::LENGTH_DELAY: return aIuScale.IU_PER_PS_PER_MM;
+    case EDA_DATA_TYPE::UNITLESS: return 1.0;
+    default: return aIuScale.IU_PER_MM;
+    }
+}
+
+
 #if 0   // No support for std::from_chars on MacOS yet
 
 bool EDA_UNIT_UTILS::ParseInternalUnits( const std::string& aInput, const EDA_IU_SCALE& aIuScale,

include/eda_units.h

@@ -129,13 +129,22 @@ namespace EDA_UNIT_UTILS
      *       on how KiCad is built.
      *
      * @param aValue A coordinate value to convert.
+     * @param aDataType The EDA_UNITS data type for @param aValue
      * @return A std::string object containing the converted value.
      */
-    KICOMMON_API std::string FormatInternalUnits( const EDA_IU_SCALE& aIuScale, int aValue );
+    KICOMMON_API std::string FormatInternalUnits( const EDA_IU_SCALE& aIuScale, int aValue,
+                                                  EDA_DATA_TYPE aDataType = EDA_DATA_TYPE::DISTANCE );
     KICOMMON_API std::string FormatInternalUnits( const EDA_IU_SCALE& aIuScale,
                                                   const VECTOR2I&     aPoint );
 
-#if 0   // No support for std::from_chars on MacOS yet
+    /**
+     * Returns the scaling parameter for the given units data type
+     *
+     * This should only be used when scaling for writing to files as it assumes metric distances are being used
+     */
+    KICOMMON_API double GetScaleForInternalUnitType( const EDA_IU_SCALE& aIuScale, EDA_DATA_TYPE aDataType );
+
+#if 0 // No support for std::from_chars on MacOS yet
     /**
      * Convert \a aInput string to internal units when reading from a file.
      *

pcbnew/pcb_io/kicad_sexpr/pcb_io_kicad_sexpr.cpp

@@ -435,9 +435,9 @@ void PCB_IO_KICAD_SEXPR::Format( const BOARD_ITEM* aItem ) const
 }
 
 
-std::string formatInternalUnits( int aValue )
+std::string formatInternalUnits( const int aValue, const EDA_DATA_TYPE aDataType = EDA_DATA_TYPE::DISTANCE )
 {
-    return EDA_UNIT_UTILS::FormatInternalUnits( pcbIUScale, aValue );
+    return EDA_UNIT_UTILS::FormatInternalUnits( pcbIUScale, aValue, aDataType );
 }
 
 
@@ -1756,7 +1756,7 @@ void PCB_IO_KICAD_SEXPR::format( const PAD* aPad ) const
 
     if( aPad->GetPadToDieDelay() != 0 )
     {
-        m_out->Print( "(die_delay %s)", formatInternalUnits( aPad->GetPadToDieDelay() ).c_str() );
+        m_out->Print( "(die_delay %s)", formatInternalUnits( aPad->GetPadToDieDelay(), EDA_DATA_TYPE::TIME ).c_str() );
     }
 
     if( aPad->GetLocalSolderMaskMargin().has_value() )

pcbnew/pcb_io/kicad_sexpr/pcb_io_kicad_sexpr.h

@@ -195,7 +195,8 @@ class PCB_IO_KICAD_SEXPR;   // forward decl
 //#define SEXPR_BOARD_FILE_VERSION    20250907  // uuids for tables
 //#define SEXPR_BOARD_FILE_VERSION    20250909  // footprint unit metadata (units/pins)
 //#define SEXPR_BOARD_FILE_VERSION    20250914  // Add support for PCB_BARCODE objects
-#define SEXPR_BOARD_FILE_VERSION      20250926  // Split via types into blind/buried/through
+//#define SEXPR_BOARD_FILE_VERSION    20250926  // Split via types into blind/buried/through
+#define SEXPR_BOARD_FILE_VERSION      20251027  // Store pad-to-die delays with correct scaling
 
 #define BOARD_FILE_HOST_VERSION       20200825  ///< Earlier files than this include the host tag
 #define LEGACY_ARC_FORMATTING         20210925  ///< These were the last to use old arc formatting

pcbnew/pcb_io/kicad_sexpr/pcb_io_kicad_sexpr_parser.cpp

@@ -211,9 +211,11 @@ int PCB_IO_KICAD_SEXPR_PARSER::parseBoardUnits()
 }
 
 
-int PCB_IO_KICAD_SEXPR_PARSER::parseBoardUnits( const char* aExpected )
+int PCB_IO_KICAD_SEXPR_PARSER::parseBoardUnits( const char*         aExpected,
+                                                const EDA_DATA_TYPE aDataType = EDA_DATA_TYPE::DISTANCE )
 {
-    auto retval = parseDouble( aExpected ) * pcbIUScale.IU_PER_MM;
+    const double scale = EDA_UNIT_UTILS::GetScaleForInternalUnitType( pcbIUScale, aDataType );
+    auto         retval = parseDouble( aExpected ) * scale;
 
     // N.B. we currently represent board units as integers.  Any values that are
     // larger or smaller than those board units represent undefined behavior for
@@ -5671,9 +5673,15 @@ PAD* PCB_IO_KICAD_SEXPR_PARSER::parsePAD( FOOTPRINT* aParent )
             break;
 
         case T_die_delay:
-            pad->SetPadToDieDelay( parseBoardUnits( T_die_delay ) );
+        {
+            if( m_requiredVersion <= 20250926 )
+                pad->SetPadToDieDelay( parseBoardUnits( T_die_delay ) );
+            else
+                pad->SetPadToDieDelay( parseBoardUnits( T_die_delay, EDA_DATA_TYPE::TIME ) );
+
             NeedRIGHT();
             break;
+        }
 
         case T_solder_mask_margin:
             pad->SetLocalSolderMaskMargin( parseBoardUnits( "local solder mask margin value" ) );

pcbnew/pcb_io/kicad_sexpr/pcb_io_kicad_sexpr_parser.h

@@ -30,6 +30,7 @@
 #ifndef _PCBNEW_PARSER_H_
 #define _PCBNEW_PARSER_H_
 
+#include <eda_units.h>
 #include <core/wx_stl_compat.h>
 #include <hashtables.h>
 #include <lib_id.h>
@@ -353,11 +354,11 @@ private:
 
     int parseBoardUnits();
 
-    int parseBoardUnits( const char* aExpected );
+    int parseBoardUnits( const char* aExpected, EDA_DATA_TYPE aDataType );
 
-    inline int parseBoardUnits( PCB_KEYS_T::T aToken )
+    inline int parseBoardUnits( const PCB_KEYS_T::T aToken, const EDA_DATA_TYPE aDataType = EDA_DATA_TYPE::DISTANCE )
     {
-        return parseBoardUnits( GetTokenText( aToken ) );
+        return parseBoardUnits( GetTokenText( aToken ), aDataType );
     }
 
     inline int parseInt()