Backed out 2 changesets (bug 1771423) for causing webcompat regressions CLOSED TREE

Backed out changeset c1d1be434427 (bug 1771423)
Backed out changeset 2b7d886f374f (bug 1771423)

dom/fetch/FetchDriver.cpp

@@ -1027,13 +1027,13 @@ FetchDriver::OnStartRequest(nsIRequest* aRequest) {
       if (NS_SUCCEEDED(rv) && !contentCharset.IsEmpty()) {
         contentType += ";charset="_ns + contentCharset;
       }
+
+      IgnoredErrorResult result;
+      response->Headers()->Append("Content-Type"_ns, contentType, result);
+      MOZ_ASSERT(!result.Failed());
     }
 
-    IgnoredErrorResult result;
-    response->Headers()->Append("Content-Type"_ns, contentType, result);
-    MOZ_ASSERT(!result.Failed());
-
-    if (contentLength >= 0) {
+    if (contentLength > 0) {
       nsAutoCString contentLenStr;
       contentLenStr.AppendInt(contentLength);
 

dom/file/uri/BlobURLChannel.cpp

@@ -26,18 +26,6 @@ BlobURLChannel::BlobURLChannel(nsIURI* aURI, nsILoadInfo* aLoadInfo)
 
 BlobURLChannel::~BlobURLChannel() = default;
 
-NS_IMETHODIMP
-BlobURLChannel::SetContentType(const nsACString& aContentType) {
-  // If the blob type is empty, set the content type of the channel to the
-  // empty string.
-  if (aContentType.IsEmpty()) {
-    mContentType.Truncate();
-    return NS_OK;
-  }
-
-  return nsBaseChannel::SetContentType(aContentType);
-}
-
 nsresult BlobURLChannel::OpenContentStream(bool aAsync,
                                            nsIInputStream** aResult,
                                            nsIChannel** aChannel) {

dom/file/uri/BlobURLChannel.h

@@ -21,8 +21,6 @@ class BlobURLChannel final : public nsBaseChannel {
  public:
   BlobURLChannel(nsIURI* aURI, nsILoadInfo* aLoadInfo);
 
-  NS_IMETHOD SetContentType(const nsACString& aContentType) override;
-
  private:
   ~BlobURLChannel() override;
 

dom/file/uri/BlobURLInputStream.cpp

@@ -13,7 +13,6 @@
 #include "mozilla/dom/ContentChild.h"
 #include "mozilla/dom/IPCBlobUtils.h"
 #include "nsStreamUtils.h"
-#include "nsMimeTypes.h"
 
 namespace mozilla::dom {
 
@@ -462,21 +461,9 @@ nsresult BlobURLInputStream::StoreBlobImplStream(
     already_AddRefed<BlobImpl> aBlobImpl, const MutexAutoLock& aProofOfLock) {
   MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread");
   const RefPtr<BlobImpl> blobImpl = aBlobImpl;
-  nsAutoString blobContentType;
-  nsAutoCString channelContentType;
-
-  blobImpl->GetType(blobContentType);
-  mChannel->GetContentType(channelContentType);
-  // A empty content type is the correct channel content type in the case of a
-  // fetch of a blob where the type was not set. It is invalid in others cases
-  // such as a XHR (See https://xhr.spec.whatwg.org/#response-mime-type). The
-  // XMLHttpRequestMainThread will set the channel content type to the correct
-  // fallback value before this point, so we need to be careful to only override
-  // it when the blob type is valid.
-  if (!blobContentType.IsEmpty() ||
-      channelContentType.EqualsLiteral(UNKNOWN_CONTENT_TYPE)) {
-    mChannel->SetContentType(NS_ConvertUTF16toUTF8(blobContentType));
-  }
+  nsAutoString contentType;
+  blobImpl->GetType(contentType);
+  mChannel->SetContentType(NS_ConvertUTF16toUTF8(contentType));
 
   auto cleanupOnExit = MakeScopeExit([&] { mChannel = nullptr; });
 

dom/xhr/XMLHttpRequestMainThread.cpp

@@ -1889,7 +1889,7 @@ XMLHttpRequestMainThread::OnStartRequest(nsIRequest* request) {
   // Fallback to 'application/octet-stream'
   nsAutoCString type;
   channel->GetContentType(type);
-  if (type.IsEmpty() || type.EqualsLiteral(UNKNOWN_CONTENT_TYPE)) {
+  if (type.EqualsLiteral(UNKNOWN_CONTENT_TYPE)) {
     channel->SetContentType(nsLiteralCString(APPLICATION_OCTET_STREAM));
   }
 

netwerk/base/nsBaseChannel.h

@@ -292,6 +292,8 @@ class nsBaseChannel
   nsCOMPtr<nsISupports> mOwner;
   nsCOMPtr<nsISupports> mSecurityInfo;
   nsCOMPtr<nsIChannel> mRedirectChannel;
+  nsCString mContentType;
+  nsCString mContentCharset;
   uint32_t mLoadFlags{LOAD_NORMAL};
   bool mQueriedProgressSink{true};
   bool mSynthProgressEvents{false};
@@ -301,8 +303,6 @@ class nsBaseChannel
   uint32_t mRedirectFlags{0};
 
  protected:
-  nsCString mContentType;
-  nsCString mContentCharset;
   nsCOMPtr<nsIURI> mURI;
   nsCOMPtr<nsILoadGroup> mLoadGroup;
   nsCOMPtr<nsILoadInfo> mLoadInfo;

netwerk/ipc/DocumentLoadListener.cpp

@@ -246,8 +246,7 @@ class ParentProcessDocumentOpenInfo final : public nsDocumentOpenInfo,
     // The one exception is nsUnknownDecoder, which works in the parent
     // (and we need to know what the content type is before we can
     // decide if it will be handled in the parent), so we run that here.
-    if (mContentType.LowerCaseEqualsASCII(UNKNOWN_CONTENT_TYPE) ||
-        mContentType.IsEmpty()) {
+    if (mContentType.LowerCaseEqualsASCII(UNKNOWN_CONTENT_TYPE)) {
       return nsDocumentOpenInfo::TryStreamConversion(aChannel);
     }
 

netwerk/protocol/viewsource/nsViewSourceChannel.cpp

@@ -471,8 +471,7 @@ nsViewSourceChannel::GetContentType(nsACString& aContentType) {
     // content decoder will then kick in automatically, and it
     // will call our SetOriginalContentType method instead of our
     // SetContentType method to set the type it determines.
-    if (!contentType.EqualsLiteral(UNKNOWN_CONTENT_TYPE) &&
-        !contentType.IsEmpty()) {
+    if (!contentType.EqualsLiteral(UNKNOWN_CONTENT_TYPE)) {
       contentType = VIEWSOURCE_CONTENT_TYPE;
     }
 

testing/web-platform/mozilla/tests/xml/blob-content-type.html

@@ -1,57 +0,0 @@
-<!doctype html>
-<meta charset=utf-8>
-<title></title>
-<script src=/resources/testharness.js></script>
-<script src=/resources/testharnessreport.js></script>
-<script>
-
-function parseBlob(blob) {
-  return new Promise(resolve => {
-    let xhr = new XMLHttpRequest();
-    xhr.open("GET", URL.createObjectURL(blob));
-    xhr.onload = () => {
-      resolve(xhr.getResponseHeader("Content-Type"));
-    }
-    xhr.send();
-  });
-}
-
-promise_test(async (t) => {
-  // Create a new blob with a valid content type
-  let blob = new Blob(["<x></x>"], { type: "application/xml" });
-
-  // The blob content type should survive
-  let blobContentType = await parseBlob(blob);
-  assert_equals(blobContentType, "application/xml");
-}, "blob object with content type is passed through");
-
-promise_test(async (t) => {
-  // Create a new blob with a invalid content type
-  let blob = new Blob(["<x></x>"], { type: "\0" });
-
-  // The blob content type should be overridden to text/xml
-  let blobContentType = await parseBlob(blob);
-  assert_equals(blobContentType, "text/xml");
-}, "blob object with invalid content type is given text/xml");
-
-promise_test(async (t) => {
-  // Create a new blob without a content type
-  let blob = new Blob(["<x></x>"]);
-
-  // The blob content type should be overridden to text/xml
-  let blobContentType = await parseBlob(blob);
-  assert_equals(blobContentType, "text/xml");
-}, "blob object with empty content type is given text/xml");
-
-promise_test(async (t) => {
-  let blob = new Blob(["<x></x>"], { type: "application/xml" });
-
-  // Create a slice of a blob without a content type
-  let slice = blob.slice(0, 6);
-
-  // The slice content type should be overridden to text/xml
-  let sliceContentType = await parseBlob(slice);
-  assert_equals(sliceContentType, "text/xml");
-}, "blob slice with empty content type is given text/xml");
-
-</script>

testing/web-platform/tests/fetch/api/basic/scheme-blob.sub.any.js

@@ -42,47 +42,7 @@ invalidRequestMethods.forEach(function(method) {
   checkKoUrl(URL.createObjectURL(blob2), method, "Fetching [" + method + "] URL.createObjectURL(blob) is KO");
 });
 
-var empty_blob = new Blob([]);
-checkFetchResponse(URL.createObjectURL(empty_blob), "", "", 0,
-                  "Fetching URL.createObjectURL(empty_blob) is OK");
-
-var empty_type_blob = new Blob([], {type: ""});
-checkFetchResponse(URL.createObjectURL(empty_type_blob), "", "", 0,
-                  "Fetching URL.createObjectURL(empty_type_blob) is OK");
-
-var empty_data_blob = new Blob([], {type: "text/plain"});
-checkFetchResponse(URL.createObjectURL(empty_data_blob), "", "text/plain", 0,
-                  "Fetching URL.createObjectURL(empty_data_blob) is OK");
-
 checkKoUrl("blob:not-backed-by-a-blob/", "GET",
            "Fetching [GET] blob:not-backed-by-a-blob/ is KO");
 
-promise_test(function(test) {
-  var blob = new Blob(["content type with invalid character"], {"type": "text/plain"});
-  let slice = blob.slice(8, 25, "\0");
-  return fetch(URL.createObjectURL(slice)).then(function (resp) {
-    assert_equals(resp.status, 200, "HTTP status is 200");
-    assert_equals(resp.type, "basic", "response type is basic");
-    assert_equals(resp.headers.get("Content-Type"), "");
-    assert_equals(resp.headers.get("Content-Length"), "17");
-    return resp.text();
-  }).then(function(bodyAsText) {
-    assert_equals(bodyAsText, "type with invalid");
-  });
-}, "Set content type to the empty string for slice with invalid content type");
-
-promise_test(function(test) {
-  var blob = new Blob(["content type that is empty"], {"type": "text/plain"});
-  let slice = blob.slice(8, 20);
-  return fetch(URL.createObjectURL(slice)).then(function (resp) {
-    assert_equals(resp.status, 200, "HTTP status is 200");
-    assert_equals(resp.type, "basic", "response type is basic");
-    assert_equals(resp.headers.get("Content-Type"), "");
-    assert_equals(resp.headers.get("Content-Length"), "12");
-    return resp.text();
-  }).then(function(bodyAsText) {
-    assert_equals(bodyAsText, "type that is");
-  });
-}, "Set content type to the empty string for slice with no content type ");
-
 done();

uriloader/base/nsURILoader.cpp

@@ -568,15 +568,7 @@ nsresult nsDocumentOpenInfo::ConvertData(nsIRequest* request,
 
 nsresult nsDocumentOpenInfo::TryStreamConversion(nsIChannel* aChannel) {
   constexpr auto anyType = "*/*"_ns;
-
-  // A empty content type should be treated like the unknown content type.
-  nsCString srcContentType(mContentType);
-  if (srcContentType.IsEmpty()) {
-    srcContentType.AssignLiteral(UNKNOWN_CONTENT_TYPE);
-  }
-
-  nsresult rv =
-      ConvertData(aChannel, m_contentListener, srcContentType, anyType);
+  nsresult rv = ConvertData(aChannel, m_contentListener, mContentType, anyType);
   if (NS_FAILED(rv)) {
     m_targetStreamListener = nullptr;
   } else if (m_targetStreamListener) {