M xywrun.c → xywrun.c

@@ -298,6 +298,8 @@ //// Returns 1 on success, 0 on error
 int xyw_eval(xyw_word start_pc)
 {
     *pc = start_pc;
+    xyw_byte handler_entry_s = 0; // Track stack depth when entering error handler
+
     if (xyw_memory[SYSTEM_STATE] & xyw_debug)
     {
         xyw_memory[SYSTEM_STATE] |= SYSTEM_STATE_DEBUG;
@@ -305,11 +307,6 @@ }
 
     while ((xyw_memory[SYSTEM_STATE] & SYSTEM_STATE_RUNNING) && *pc < SYSTEM_MEMORY_START)
     {
-        if (xyw_memory[SYSTEM_ERROR] == XYW_ERROR_NONE)
-        {
-            // Clear error state if no error
-            xyw_memory[SYSTEM_STATE] &= ~SYSTEM_STATE_ERROR;
-        }
         if (xyw_memory[SYSTEM_ERROR] != XYW_ERROR_NONE && !(xyw_memory[SYSTEM_STATE] & SYSTEM_STATE_ERROR))
         {
             // An error has occurred, update state
@@ -318,6 +315,7 @@ xyw_word on_error_handler = XYW_PEEKW(&xyw_memory[SYSTEM_ON_ERROR]);
             // If an error handler is set, jump to it
             if (on_error_handler != 0)
             {
+                handler_entry_s = *s; // Record stack depth before pushing return address
                 ss_pushw(*pc);
                 *pc = on_error_handler;
             }
@@ -375,7 +373,13 @@ /* ROT */ OPC_SR2(0x1B, PUSH(b); PUSH(POP()); PUSH(a));
             /* JMP */ OPC_SR1(0x1C, , *pc = ADDR(ARG)-1;);
             /* JCN */ OPC_SR1(0x1D, , xyw_word addr = ADDR(ARG); xyw_byte cond = us_pop(); if (cond) { *pc = addr-1; });
             /* JSR */ OPC_SR1(0x1E, xyw_word addr = ADDR(ARG),  ss_pushw(*pc+1); *pc = addr-1;);
-            /* RTS */ case 0x1F: *pc = ss_popw()-1; break;
+            /* RTS */ case 0x1F: 
+                *pc = ss_popw()-1; 
+                // If returning from error handler, clear flag to allow re-trigger
+                if ((xyw_memory[SYSTEM_STATE] & SYSTEM_STATE_ERROR) && *s == handler_entry_s) {
+                    xyw_memory[SYSTEM_STATE] &= ~SYSTEM_STATE_ERROR;
+                }
+                break;
             // clang-format on
         }
         (*pc)++;