Prevent guest views from issuing a search for empty text.

ppapi/cpp/private/find_private.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ppapi/cpp/private/find_private.h"
 
 #include "ppapi/c/private/ppb_find_private.h"
 #include "ppapi/cpp/instance.h"
 #include "ppapi/cpp/module.h"
 #include "ppapi/cpp/module_impl.h"
 #include "ppapi/cpp/rect.h"
 
 namespace pp {
 
 namespace {
 
 template <> const char* interface_name<PPB_Find_Private>() {
   return PPB_FIND_PRIVATE_INTERFACE;
 }
 
 static const char kPPPFindInterface[] = PPP_FIND_PRIVATE_INTERFACE;
 
 PP_Bool StartFind(PP_Instance instance,
                   const char* text,
                   PP_Bool case_sensitive) {
   void* object = Instance::GetPerInstanceObject(instance, kPPPFindInterface);
   if (!object)
     return PP_FALSE;
+  if (!text || text[0] == '\0') {
+    PP_NOTREACHED();
+    return PP_FALSE;
+  }
   bool return_value = static_cast<Find_Private*>(object)->StartFind(
       text, PP_ToBool(case_sensitive));
   return PP_FromBool(return_value);
 }
 
 void SelectFindResult(PP_Instance instance, PP_Bool forward) {
   void* object = Instance::GetPerInstanceObject(instance, kPPPFindInterface);
   if (object)
     static_cast<Find_Private*>(object)->SelectFindResult(PP_ToBool(forward));
 }
@@ skipping 51 matching lines @@
                                              tickmarks.end());
     PP_Rect* array =
         tickmarks_converted.empty() ? NULL : &tickmarks_converted[0];
     get_interface<PPB_Find_Private>()->SetTickmarks(
         associated_instance_.pp_instance(), array,
         static_cast<uint32_t>(tickmarks.size()));
   }
 }
 
 }  // namespace pp