Prevent guest views from issuing a search for empty text.

extensions/browser/api/guest_view/web_view/web_view_internal_api.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 "extensions/browser/api/guest_view/web_view/web_view_internal_api.h"
 
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/public/browser/browser_context.h"
@@ skipping 27 matching lines @@
 namespace {
 
 const char kAppCacheKey[] = "appcache";
 const char kCacheKey[] = "cache";
 const char kCookiesKey[] = "cookies";
 const char kFileSystemsKey[] = "fileSystems";
 const char kIndexedDBKey[] = "indexedDB";
 const char kLocalStorageKey[] = "localStorage";
 const char kWebSQLKey[] = "webSQL";
 const char kSinceKey[] = "since";
+
+const char kDuplicatedContentScriptNamesError[] =
+    "The given content script name already exists.";
+const char kEmptyFindTextError[] = "Find called with no text";
 const char kLoadFileError[] = "Failed to load file: \"*\". ";
 const char kViewInstanceIdError[] = "view_instance_id is missing.";
-const char kDuplicatedContentScriptNamesError[] =
-    "The given content script name already exists.";
 
 uint32 MaskForKey(const char* key) {
   if (strcmp(key, kAppCacheKey) == 0)
     return webview::WEB_VIEW_REMOVE_DATA_MASK_APPCACHE;
   if (strcmp(key, kCacheKey) == 0)
     return webview::WEB_VIEW_REMOVE_DATA_MASK_CACHE;
   if (strcmp(key, kCookiesKey) == 0)
     return webview::WEB_VIEW_REMOVE_DATA_MASK_COOKIES;
   if (strcmp(key, kFileSystemsKey) == 0)
     return webview::WEB_VIEW_REMOVE_DATA_MASK_FILE_SYSTEMS;
@@ skipping 563 matching lines @@
 
 bool WebViewInternalFindFunction::RunAsyncSafe(WebViewGuest* guest) {
   scoped_ptr<web_view_internal::Find::Params> params(
       web_view_internal::Find::Params::Create(*args_));
   EXTENSION_FUNCTION_VALIDATE(params.get());
 
   // Convert the std::string search_text to string16.
   base::string16 search_text;
   base::UTF8ToUTF16(
       params->search_text.c_str(), params->search_text.length(), &search_text);
+  if (search_text.empty()) {

[Fady Samuel, 2015/09/26 00:14:34]

I don't think this is the correct solution. I think this breaks the <webview>
Find API. I believe you can provide find with an empty string to "FindNext".
paulmeyer@ wrote this API. Passing this bug along to him.

[Lei Zhang, 2015/09/26 00:22:01]

You are referring to https://developer.chrome.com/apps/tags/webview#method-find
right?

What's the point of searching for no text? I guess the alternative is to just
immediately reply "successfully" with no results.

[Charlie Reis, 2015/09/28 19:35:17]

It does seem like a nonsensical case to me.  I'd be ok with either returning 0
results or an error, depending on what the <webview> folks want their API to do.

+    error_ = kEmptyFindTextError;
+    SendResponse(false);
+    return true;
+  }
 
   // Set the find options to their default values.
   blink::WebFindOptions options;
   if (params->options) {
     options.forward =
         params->options->backward ? !*params->options->backward : true;
     options.matchCase =
         params->options->match_case ? *params->options->match_case : false;
   }
 
@@ skipping 247 matching lines @@
   // Will finish asynchronously.
   return true;
 }
 
 void WebViewInternalClearDataFunction::ClearDataDone() {
   Release();  // Balanced in RunAsync().
   SendResponse(true);
 }
 
 }  // namespace extensions