Checking tooltip against empty before adding Unicode marks

webkit/glue/chrome_client_impl.cc

 // Copyright (c) 2006-2008 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 "config.h"
 
 #include "base/compiler_specific.h"
 
 MSVC_PUSH_WARNING_LEVEL(0);
 #include "AccessibilityObject.h"
@@ skipping 495 matching lines @@
       delegate->UpdateTargetURL(webview_, GURL());
     }
   }
 }
 
 void ChromeClientImpl::setToolTip(const WebCore::String& tooltip_text,
                                   WebCore::TextDirection dir) {
   if (webview_->delegate()) {
     std::wstring tooltip_text_as_wstring =
       webkit_glue::StringToStdWString(tooltip_text);
-    if (dir == WebCore::LTR) {
-      // Force the tooltip to have LTR directionality.
-      tooltip_text_as_wstring.insert(0, 1, WebCore::leftToRightEmbed);
-      tooltip_text_as_wstring.push_back(WebCore::popDirectionalFormatting);
-    } else {
-      // Force the tooltip to have RTL directionality.
-      tooltip_text_as_wstring.insert(0, 1, WebCore::rightToLeftEmbed);
-      tooltip_text_as_wstring.push_back(WebCore::popDirectionalFormatting);
+    if (!tooltip_text_as_wstring.empty()) {
+      if (dir == WebCore::LTR) {
+        // Force the tooltip to have LTR directionality.
+        tooltip_text_as_wstring.insert(0, 1, WebCore::leftToRightEmbed);
+        tooltip_text_as_wstring.push_back(WebCore::popDirectionalFormatting);
+      } else {
+        // Force the tooltip to have RTL directionality.
+        tooltip_text_as_wstring.insert(0, 1, WebCore::rightToLeftEmbed);
+        tooltip_text_as_wstring.push_back(WebCore::popDirectionalFormatting);
+      }
     }
     webview_->delegate()->SetTooltipText(webview_, tooltip_text_as_wstring);
   }
 }
 
 void ChromeClientImpl::print(WebCore::Frame* frame) {
   WebViewDelegate* delegate = webview_->delegate();
   if (delegate) {
     delegate->ScriptedPrint(WebFrameImpl::FromFrame(frame));
   }
@@ skipping 93 matching lines @@
         break;
       default:
         NOTREACHED();
     }
   }
 
   info->itemHeight = popup_container->menuItemHeight();
   info->selectedIndex = popup_container->selectedIndex();
   info->items.swap(output_items);
 }