1 files changed, 109 insertions, 0 deletions
diff --git a/intl/uconv/tests/gtest/TestShortRead.cpp b/intl/uconv/tests/gtest/TestShortRead.cpp
new file mode 100644
index 0000000000..393f5e0027
--- /dev/null
+++ b/intl/uconv/tests/gtest/TestShortRead.cpp
@@ -0,0 +1,109 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "gtest/gtest.h"
+#include "mozilla/ErrorNames.h"
+#include "nsCOMPtr.h"
+#include "nsConverterInputStream.h"
+#include "nsIInputStream.h"
+#include "nsISupports.h"
+#include "nsStringStream.h"
+
+namespace {
+
+class ShortReadWrapper final : public nsIInputStream {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIINPUTSTREAM
+
+  template <size_t N>
+  ShortReadWrapper(const uint32_t (&aShortReads)[N],
+                   nsIInputStream* aBaseStream)
+      : mShortReadIter(std::begin(aShortReads)),
+        mShortReadEnd(std::end(aShortReads)),
+        mBaseStream(aBaseStream) {}
+
+  ShortReadWrapper(const ShortReadWrapper&) = delete;
+  ShortReadWrapper& operator=(const ShortReadWrapper&) = delete;
+
+ private:
+  ~ShortReadWrapper() = default;
+
+  const uint32_t* mShortReadIter;
+  const uint32_t* mShortReadEnd;
+  nsCOMPtr<nsIInputStream> mBaseStream;
+};
+
+NS_IMPL_ISUPPORTS(ShortReadWrapper, nsIInputStream)
+
+NS_IMETHODIMP
+ShortReadWrapper::Close() { return mBaseStream->Close(); }
+
+NS_IMETHODIMP
+ShortReadWrapper::Available(uint64_t* aAvailable) {
+  nsresult rv = mBaseStream->Available(aAvailable);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (mShortReadIter != mShortReadEnd) {
+    *aAvailable = std::min(uint64_t(*mShortReadIter), *aAvailable);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ShortReadWrapper::StreamStatus() { return mBaseStream->StreamStatus(); }
+
+NS_IMETHODIMP
+ShortReadWrapper::Read(char* aBuf, uint32_t aCount, uint32_t* _retval) {
+  if (mShortReadIter != mShortReadEnd) {
+    aCount = std::min(*mShortReadIter, aCount);
+  }
+
+  nsresult rv = mBaseStream->Read(aBuf, aCount, _retval);
+  if (NS_SUCCEEDED(rv) && mShortReadIter != mShortReadEnd) {
+    ++mShortReadIter;
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+ShortReadWrapper::ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
+                               uint32_t aCount, uint32_t* _retval) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+ShortReadWrapper::IsNonBlocking(bool* _retval) {
+  return mBaseStream->IsNonBlocking(_retval);
+}
+
+}  // namespace
+
+TEST(ConverterStreamShortRead, ShortRead)
+{
+  uint8_t bytes[] = {0xd8, 0x35, 0xdc, 0x20};
+  nsCOMPtr<nsIInputStream> baseStream;
+  ASSERT_TRUE(NS_SUCCEEDED(NS_NewByteInputStream(getter_AddRefs(baseStream),
+                                                 AsChars(mozilla::Span(bytes)),
+                                                 NS_ASSIGNMENT_COPY)));
+
+  static const uint32_t kShortReads[] = {1, 2, 1};
+  nsCOMPtr<nsIInputStream> shortStream =
+      new ShortReadWrapper(kShortReads, baseStream);
+
+  RefPtr<nsConverterInputStream> unicharStream = new nsConverterInputStream();
+  ASSERT_TRUE(NS_SUCCEEDED(
+      unicharStream->Init(shortStream, "UTF-16BE", 4096,
+                          nsIConverterInputStream::ERRORS_ARE_FATAL)));
+
+  uint32_t read;
+  nsAutoString result;
+  ASSERT_TRUE(
+      NS_SUCCEEDED(unicharStream->ReadString(UINT32_MAX, result, &read)));
+
+  ASSERT_EQ(read, 2u);
+  ASSERT_TRUE(result == u"\U0001d420");
+}