Do not produce BR elements on pasting plain text in TEXTAREA

third_party/WebKit/Source/core/editing/serializers/Serialization.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009, 2010, 2011 Google Inc. All rights reserved.
  * Copyright (C) 2011 Igalia S.L.
  * Copyright (C) 2011 Motorola Mobility. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
@@ skipping 449 matching lines @@
     Document& document = context.document();
     RefPtrWillBeRawPtr<DocumentFragment> fragment = document.createDocumentFragment();
 
     if (text.isEmpty())
         return fragment.release();
 
     String string = text;
     string.replace("\r\n", "\n");
     string.replace('\r', '\n');
 
-    if (shouldPreserveNewline(context)) {
+    if (!isRichlyEditablePosition(context.startPosition()) || shouldPreserveNewline(context)) {
         fragment->appendChild(document.createTextNode(string));
         if (string.endsWith('\n')) {
             RefPtrWillBeRawPtr<HTMLBRElement> element = HTMLBRElement::create(document);
             element->setAttribute(classAttr, AppleInterchangeNewline);
             fragment->appendChild(element.release());
         }
         return fragment.release();
     }
 
     // A string with no newlines gets added inline, rather than being put into a paragraph.
     if (string.find('\n') == kNotFound) {
         fillContainerFromString(fragment.get(), string);
         return fragment.release();
     }
 
     // Break string into paragraphs. Extra line breaks turn into empty paragraphs.
     Element* block = enclosingBlock(context.startPosition().nodeAsRangeFirstNode());
     bool useClonesOfEnclosingBlock = block
         && !isHTMLBodyElement(*block)
         && !isHTMLHtmlElement(*block)
         && block != rootEditableElementOf(context.startPosition());
-    bool useLineBreak = enclosingTextFormControl(context.startPosition());
 
     Vector<String> list;
     string.split('\n', true, list); // true gets us empty strings in the list
     size_t numLines = list.size();
     for (size_t i = 0; i < numLines; ++i) {
         const String& s = list[i];
 
         RefPtrWillBeRawPtr<Element> element = nullptr;
         if (s.isEmpty() && i + 1 == numLines) {
             // For last line, use the "magic BR" rather than a P.
             element = HTMLBRElement::create(document);
             element->setAttribute(classAttr, AppleInterchangeNewline);
-        } else if (useLineBreak) {
-            element = HTMLBRElement::create(document);
-            fillContainerFromString(fragment.get(), s);
         } else {
             if (useClonesOfEnclosingBlock)
                 element = block->cloneElementWithoutChildren();
             else
                 element = createDefaultParagraphElement(document);
             fillContainerFromString(element.get(), s);
         }
         fragment->appendChild(element.release());
     }
     return fragment.release();
@@ skipping 180 matching lines @@
     RefPtrWillBeRawPtr<Text> textNext = toText(next);
     textNode->appendData(textNext->data());
     if (textNext->parentNode()) // Might have been removed by mutation event.
         textNext->remove(exceptionState);
 }
 
 template class CORE_TEMPLATE_EXPORT CreateMarkupAlgorithm<EditingStrategy>;
 template class CORE_TEMPLATE_EXPORT CreateMarkupAlgorithm<EditingInFlatTreeStrategy>;
 
 } // namespace blink