Interpreter: Allow active G43 for tools with all zero offsets

Current behavior switches to G49 if G43 is commanded with loaded
tool offset values all zero.

Behavior for G43.1 and G43.2 remains unchanged.

Author: Sigma1912

src/emc/rs274ngc/interp_convert.cc

@@ -6199,7 +6199,8 @@ int Interp::convert_tool_length_offset(int g_code,       //!< g_code being execu
   int idx;
   EmcPose tool_offset;
   ZERO_EMC_POSE(tool_offset);
-
+  settings->g43_with_zero_offset = 0;
+  
   CHKS((settings->cutter_comp_side != CUTTER_COMP::OFF),
        (_("Cannot change tool offset with cutter radius compensation on")));
   if (g_code == G_49) {
@@ -6237,6 +6238,10 @@ int Interp::convert_tool_length_offset(int g_code,       //!< g_code being execu
     tool_offset.u = USER_TO_PROGRAM_LEN(settings->tool_table[idx].offset.u);
     tool_offset.v = USER_TO_PROGRAM_LEN(settings->tool_table[idx].offset.v);
     tool_offset.w = USER_TO_PROGRAM_LEN(settings->tool_table[idx].offset.w);
+    settings->g43_with_zero_offset =
+      (settings->tool_offset.tran.x || settings->tool_offset.tran.y || settings->tool_offset.tran.z ||
+       settings->tool_offset.a || settings->tool_offset.b || settings->tool_offset.c ||
+       settings->tool_offset.u || settings->tool_offset.v || settings->tool_offset.w);
   } else if (g_code == G_43_1) {
     tool_offset = settings->tool_offset;
     idx = -1;

src/emc/rs274ngc/interp_internal.hh

@@ -759,6 +759,7 @@ struct setup
   CANON_TOOL_TABLE tool_table[CANON_POCKETS_MAX];      // index is pocket number
   double traverse_rate;         // rate for traverse motions
   double orient_offset;         // added to M19 R word, from [RS274NGC]ORIENT_OFFSET
+  bool g43_with_zero_offset;    // added to allow active G43 with tool offset values all zero
 
   /* stuff for subroutines and control structures */
   int defining_sub;                  // true if in a subroutine defn

src/emc/rs274ngc/interp_write.cc

@@ -108,9 +108,10 @@ int Interp::write_g_codes(block_pointer block,   //!< pointer to a block of RS27
      7) ? (530 + (10 * settings->origin_index)) : (584 +
                                                    settings->origin_index);
   settings->active_g_codes[9] =
-    (settings->tool_offset.tran.x || settings->tool_offset.tran.y || settings->tool_offset.tran.z ||
-     settings->tool_offset.a || settings->tool_offset.b || settings->tool_offset.c ||
-     settings->tool_offset.u || settings->tool_offset.v || settings->tool_offset.w) ? G_43 : G_49;
+    (settings->g43_with_zero_offset ||
+     settings->tool_offset.tran.x || settings->tool_offset.tran.y || settings->tool_offset.tran.z ||
+	 settings->tool_offset.a || settings->tool_offset.b || settings->tool_offset.c ||
+	 settings->tool_offset.u || settings->tool_offset.v || settings->tool_offset.w) ? G_43 : G_49;
   settings->active_g_codes[10] = (settings->retract_mode == RETRACT_MODE::OLD_Z) ? G_98 : G_99;
   // Three modes:  G_64, G_61, G_61_1 or CANON_CONTINUOUS/EXACT_PATH/EXACT_STOP
   settings->active_g_codes[11] =
@@ -279,7 +280,8 @@ int Interp::write_state_tag(block_pointer block,
     state.flags[GM_FLAG_G92_IS_APPLIED] = settings->parameters[5210];
 
     state.flags[GM_FLAG_TOOL_OFFSETS_ON] =
-	(settings->tool_offset.tran.x ||
+    (settings->g43_with_zero_offset ||
+     settings->tool_offset.tran.x ||
 	 settings->tool_offset.tran.y ||
 	 settings->tool_offset.tran.z ||
 	 settings->tool_offset.a ||