Fix context level info in for-loops

runtime/vm/object.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 13694 matching lines @@
     THR_Print("Context@null\n");
     return;
   }
 
   IndentN(indent);
   THR_Print("Context@%p vars(%" Pd ") {\n", this->raw(), num_variables());
   Object& obj = Object::Handle();
   for (intptr_t i = 0; i < num_variables(); i++) {
     IndentN(indent + 2);
     obj = At(i);
-    THR_Print("[%" Pd "] = %s\n", i, obj.ToCString());
+    const char* s = obj.ToCString();
+    if (strlen(s) > 50) {
+      THR_Print("[%" Pd "] = [first 50 chars:] %.50s...\n", i, s);
+    } else {
+      THR_Print("[%" Pd "] = %s\n", i, s);
+    }
   }
 
   const Context& parent_ctx = Context::Handle(parent());
   if (!parent_ctx.IsNull()) {
     parent_ctx.Dump(indent + 2);
   }
   IndentN(indent);
   THR_Print("}\n");
 }
 
@@ skipping 8145 matching lines @@
   return UserTag::null();
 }
 
 
 const char* UserTag::ToCString() const {
   const String& tag_label = String::Handle(label());
   return tag_label.ToCString();
 }
 
 }  // namespace dart