fix(inspector): revert pointer before calling step_end

MIGRATION_GUIDE.md

@@ -1,4 +1,10 @@
 
+# v80 tag (revm v27.0.0) -> v81 tag ( revm v27.0.1)
+
+* Inspector fn `step_end` is now called even if Inspector `step` sets the action. Previously this was not the  case
+    * https://github.com/bluealloy/revm/pull/2687
+    * this additionally fixes panic bug where `bytecode.opcode()` would panic in `step_end`
+
 # v70 tag (revm v22.0.2) -> v71 tag ( revm v23.0.0)
 
 * Removal of `EvmData`.

crates/inspector/src/gas.rs

@@ -92,6 +92,7 @@ mod tests {
     #[derive(Default, Debug)]
     struct StackInspector {
         pc: usize,
+        opcode: u8,
         gas_inspector: GasInspector,
         gas_remaining_steps: Vec<(usize, u64)>,
     }
@@ -103,10 +104,13 @@ mod tests {
 
         fn step(&mut self, interp: &mut Interpreter<INTR>, _context: &mut CTX) {
             self.pc = interp.bytecode.pc();
+            self.opcode = interp.bytecode.opcode();
             self.gas_inspector.step(&interp.gas);
         }
 
         fn step_end(&mut self, interp: &mut Interpreter<INTR>, _context: &mut CTX) {
+            interp.bytecode.pc();
+            interp.bytecode.opcode();
             self.gas_inspector.step_end(&mut interp.gas);
             self.gas_remaining_steps
                 .push((self.pc, self.gas_inspector.gas_remaining()));

crates/inspector/src/handler.rs

@@ -215,11 +215,18 @@ where
             log_num = new_log;
         }
 
+        // if loops is ending, break the loop so we can revert to the previous pointer and then call step_end.
+        if interpreter.bytecode.is_end() {
+            break;
+        }
+
         // Call step_end.
         inspector.step_end(interpreter, context);
     }
 
     interpreter.bytecode.revert_to_previous_pointer();
+    // call step_end again to handle the last instruction
+    inspector.step_end(interpreter, context);
 
     let next_action = interpreter.take_next_action();