Check that function being patched has no activations on any thread stack

src/debug-delay.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1968 matching lines @@
     if (scripts[i].id == script_id) {
       the_script = scripts[i];
     }
   }
   if (!the_script) {
     response.failed('Script not found');
     return;
   }
   
   var change_log = new Array();
-  Debug.LiveEditChangeScript(the_script, change_pos, change_len, new_string,
-                             change_log);
-      
+  try {
+    Debug.LiveEditChangeScript(the_script, change_pos, change_len, new_string,
+                               change_log);
+  } catch (e) {
+    if (e instanceof Debug.LiveEditChangeScript.Failure) {
+      // Let's treat it as a "success" so that body with change_log will be
+      // sent back. "change_log" will have "failure" field set.
+      change_log.push( { failure: true } ); 
+    } else {
+      throw e;
+    }
+  }
   response.body = {change_log: change_log};
 };
 
 
 // Check whether the previously processed command caused the VM to become
 // running.
 DebugCommandProcessor.prototype.isRunning = function() {
   return this.running_;
 }
 
@@ skipping 110 matching lines @@
     case 'string':
     case 'number':
       json = value;
       break
 
     default:
       json = null;
   }
   return json;
 }