From 622a4f29a782e022d2a394eb1f1d1dcf7184bc36 Mon Sep 17 00:00:00 2001
From: Kenneth Myhra <kennethmyhra@gmail.com>
Date: Sun, 24 Jul 2022 15:43:33 +0200
Subject: [PATCH] LibWeb: Add public get accessor function for Blob's internal
 ByteBuffer

Blob::bytes() returns the ReadonlyBytes representation of our internal
ByteBuffer.

This change requires us to ByteBuffer::copy() Blob's ReadonlyBytes to a
ByteBuffer in XHR::send() and corresponding error handling of the copy
operation.

This removes the need for Blob to declare XMLHttpRequest as a friend
class.
---
 Userland/Libraries/LibWeb/FileAPI/Blob.cpp      |  2 +-
 Userland/Libraries/LibWeb/FileAPI/Blob.h        |  4 ++--
 .../Libraries/LibWeb/XHR/XMLHttpRequest.cpp     | 17 +++++++++++++----
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/Userland/Libraries/LibWeb/FileAPI/Blob.cpp b/Userland/Libraries/LibWeb/FileAPI/Blob.cpp
index 9e1815511a..5f9a1bce82 100644
--- a/Userland/Libraries/LibWeb/FileAPI/Blob.cpp
+++ b/Userland/Libraries/LibWeb/FileAPI/Blob.cpp
@@ -76,7 +76,7 @@ ErrorOr<ByteBuffer> Blob::process_blob_parts(Vector<BlobPart> const& blob_parts)
             },
             // 3. If element is a Blob, append the bytes it represents to bytes.
             [&](NonnullRefPtr<Blob> const& blob) -> ErrorOr<void> {
-                return bytes.try_append(blob->m_byte_buffer.bytes());
+                return bytes.try_append(blob->bytes());
             }));
     }
     return bytes;
diff --git a/Userland/Libraries/LibWeb/FileAPI/Blob.h b/Userland/Libraries/LibWeb/FileAPI/Blob.h
index 0035f243f5..4947323544 100644
--- a/Userland/Libraries/LibWeb/FileAPI/Blob.h
+++ b/Userland/Libraries/LibWeb/FileAPI/Blob.h
@@ -48,14 +48,14 @@ public:
 
     virtual JS::Object* create_wrapper(JS::GlobalObject&);
 
+    ReadonlyBytes bytes() const { return m_byte_buffer.bytes(); }
+
 private:
     Blob() = default;
     static ErrorOr<ByteBuffer> process_blob_parts(Vector<BlobPart> const& blob_parts);
 
     ByteBuffer m_byte_buffer {};
     String m_type {};
-
-    friend class XHR::XMLHttpRequest;
 };
 
 }
diff --git a/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp b/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp
index 9bd319bd1c..e16b9e756d 100644
--- a/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp
+++ b/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp
@@ -475,10 +475,19 @@ DOM::ExceptionOr<void> XMLHttpRequest::send(Optional<XMLHttpRequestBodyInit> bod
     auto request = LoadRequest::create_for_url_on_page(request_url, m_window->page());
     request.set_method(m_method);
     if (body_with_type.has_value()) {
-        body_with_type->body.source().visit(
-            [&](ByteBuffer const& buffer) { request.set_body(buffer); },
-            [&](NonnullRefPtr<FileAPI::Blob> const& blob) { request.set_body(blob->m_byte_buffer); },
-            [](auto&) {});
+        TRY_OR_RETURN_OOM(body_with_type->body.source().visit(
+            [&](ByteBuffer const& buffer) -> ErrorOr<void> {
+                request.set_body(buffer);
+                return {};
+            },
+            [&](NonnullRefPtr<FileAPI::Blob> const& blob) -> ErrorOr<void> {
+                auto byte_buffer = TRY(ByteBuffer::copy(blob->bytes()));
+                request.set_body(byte_buffer);
+                return {};
+            },
+            [](auto&) -> ErrorOr<void> {
+                return {};
+            }));
         if (body_with_type->type.has_value())
             request.set_header("Content-Type", String { body_with_type->type->span() });
     }