Find the correct function for script break points

src/runtime.cc

 // Copyright 2006-2009 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 6803 matching lines @@
             start_position = shared->start_position();
           }
           if (start_position <= position &&
               position <= shared->end_position()) {
             // If there is no candidate or this function is within the current
             // candidate this is the new candidate.
             if (target.is_null()) {
               target_start_position = start_position;
               target = shared;
             } else {
-              if (target_start_position < start_position &&
-                  shared->end_position() < target->end_position()) {
+              if (target_start_position == start_position &&
+                  shared->end_position() == target->end_position()) {
+                  // If a top-level function contain only one function
+                  // declartion the source for the top-level and the function is
+                  // the same. In that case prefer the non top-level function.
+                if (!shared->is_toplevel()) {
+                  target_start_position = start_position;
+                  target = shared;
+                }
+              } else if (target_start_position <= start_position &&
+                         shared->end_position() <= target->end_position()) {
+                // This containment check includes equality as a function inside
+                // a top-level function can share either start or end position
+                // with the top-level function.
                 target_start_position = start_position;
                 target = shared;
               }
             }
           }
 
           // Keep track of the last function in the script.
           if (last.is_null() ||
               shared->end_position() > last->start_position()) {
             last = shared;
@@ skipping 861 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal