[Fetch API] Appending headers of the same name should have their values

third_party/WebKit/Source/modules/fetch/FetchHeaderList.cpp

Index: third_party/WebKit/Source/modules/fetch/FetchHeaderList.cpp
diff --git a/third_party/WebKit/Source/modules/fetch/FetchHeaderList.cpp b/third_party/WebKit/Source/modules/fetch/FetchHeaderList.cpp
index ca24581c50d6d8947f534060708b79cfea3f77c1..d3a0ee7235986bd4f1a64654fe4971be5ac023ff 100644
--- a/third_party/WebKit/Source/modules/fetch/FetchHeaderList.cpp
+++ b/third_party/WebKit/Source/modules/fetch/FetchHeaderList.cpp
@@ -30,7 +30,8 @@ void FetchHeaderList::append(const String& name, const String& value) {
   // "To append a name/value (|name|/|value|) pair to a header list (|list|),
   // append a new header whose name is |name|, byte lowercased, and value is
   // |value|, to |list|."
-  m_headerList.append(WTF::wrapUnique(new Header(name.lower(), value)));
+  if (!value.isEmpty())

[jsbell, 2016/12/16 22:29:37]

This seems incorrect - the caller (Headers::append) should validate this first.

+    m_headerList.append(WTF::wrapUnique(new Header(name.lower(), value)));
 }
 
 void FetchHeaderList::set(const String& name, const String& value) {
@@ -87,13 +88,18 @@ void FetchHeaderList::remove(const String& name) {
 
 bool FetchHeaderList::get(const String& name, String& result) const {
   const String lowercasedName = name.lower();
-  for (size_t i = 0; i < m_headerList.size(); ++i) {
-    if (m_headerList[i]->first == lowercasedName) {
-      result = m_headerList[i]->second;
-      return true;
+  for (const auto& header : m_headerList) {
+    DCHECK(!header->second.isEmpty());
+    if (header->first == lowercasedName) {
+      if (result.isEmpty()) {
+        result = header->second;
+      } else {
+        result.append(",");
+        result.append(header->second);
+      }
     }
   }
-  return false;
+  return !result.isEmpty();
 }
 
 void FetchHeaderList::getAll(const String& name, Vector<String>& result) const {