Fix a crash by AdvanceToNextMisspelling command (⌘-;) with empty INPUT

third_party/WebKit/Source/core/editing/spellcheck/SpellCheckerTest.cpp

+// Copyright 2016 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 "core/editing/spellcheck/SpellChecker.h"
+
+#include "core/editing/EditingTestBase.h"
+#include "core/editing/Editor.h"
+#include "core/frame/Settings.h"
+
+namespace blink {
+
+class SpellCheckerTest : public EditingTestBase {
+};
+
+TEST_F(SpellCheckerTest, AdvanceToNextMisspellingWithEmptyInputNoCrash)
+{
+    setBodyContent("<input placeholder='placeholder'>abc");
+    updateLayoutAndStyleForPainting();
+    RefPtrWillBeRawPtr<Element> input = document().querySelector("input", ASSERT_NO_EXCEPTION);
+    input->focus();
+    document().settings()->setUnifiedTextCheckerEnabled(true);
+    // Do not crash in AdvanceToNextMisspelling command.
+    EXPECT_TRUE(document().frame()->editor().executeCommand("AdvanceToNextMisspelling"));
+    document().settings()->setUnifiedTextCheckerEnabled(false);
+}
+
+} // namespace blink