diff -r 000000000000 -r 6474c204b198 xpcom/tests/TestTArray.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/tests/TestTArray.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,1066 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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 "mozilla/ArrayUtils.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include "nsTArray.h"
+#include "nsAutoPtr.h"
+#include "nsStringAPI.h"
+#include "nsDirectoryServiceDefs.h"
+#include "nsDirectoryServiceUtils.h"
+#include "nsComponentManagerUtils.h"
+#include "nsXPCOM.h"
+#include "nsIFile.h"
+
+using namespace mozilla;
+
+namespace TestTArray {
+
+// Define this so we can use test_basic_array in test_comptr_array
+template <class T>
+inline bool operator<(const nsCOMPtr<T>& lhs, const nsCOMPtr<T>& rhs) {
+  return lhs.get() < rhs.get();
+}
+
+//----
+
+template <class ElementType>
+static bool test_basic_array(ElementType *data,
+                               uint32_t dataLen,
+                               const ElementType& extra) {
+  nsTArray<ElementType> ary;
+  ary.AppendElements(data, dataLen);
+  if (ary.Length() != dataLen) {
+    return false;
+  }
+  if (!(ary == ary)) {
+    return false;
+  }
+  uint32_t i;
+  for (i = 0; i < ary.Length(); ++i) {
+    if (ary[i] != data[i])
+      return false;
+  }
+  for (i = 0; i < ary.Length(); ++i) {
+    if (ary.SafeElementAt(i, extra) != data[i])
+      return false;
+  }
+  if (ary.SafeElementAt(ary.Length(), extra) != extra ||
+      ary.SafeElementAt(ary.Length() * 10, extra) != extra)
+    return false;
+  // ensure sort results in ascending order
+  ary.Sort();
+  uint32_t j = 0, k = ary.IndexOfFirstElementGt(extra);
+  if (k != 0 && ary[k-1] == extra)
+    return false;
+  for (i = 0; i < ary.Length(); ++i) {
+    k = ary.IndexOfFirstElementGt(ary[i]);
+    if (k == 0 || ary[k-1] != ary[i])
+      return false;
+    if (k < j)
+      return false;
+    j = k;
+  }
+  for (i = ary.Length(); --i; ) {
+    if (ary[i] < ary[i - 1])
+      return false;
+    if (ary[i] == ary[i - 1])
+      ary.RemoveElementAt(i);
+  }
+  if (!(ary == ary)) {
+    return false;
+  }
+  for (i = 0; i < ary.Length(); ++i) {
+    if (ary.BinaryIndexOf(ary[i]) != i)
+      return false;
+  }
+  if (ary.BinaryIndexOf(extra) != ary.NoIndex)
+    return false;
+  uint32_t oldLen = ary.Length();
+  ary.RemoveElement(data[dataLen / 2]);
+  if (ary.Length() != (oldLen - 1))
+    return false;
+  if (!(ary == ary))
+    return false;
+
+  uint32_t index = ary.Length() / 2;
+  if (!ary.InsertElementAt(index, extra))
+    return false;
+  if (!(ary == ary))
+    return false;
+  if (ary[index] != extra)
+    return false;
+  if (ary.IndexOf(extra) == UINT32_MAX)
+    return false;
+  if (ary.LastIndexOf(extra) == UINT32_MAX)
+    return false;
+  // ensure proper searching
+  if (ary.IndexOf(extra) > ary.LastIndexOf(extra))
+    return false;
+  if (ary.IndexOf(extra, index) != ary.LastIndexOf(extra, index))
+    return false;
+
+  nsTArray<ElementType> copy(ary);
+  if (!(ary == copy))
+    return false;
+  for (i = 0; i < copy.Length(); ++i) {
+    if (ary[i] != copy[i])
+      return false;
+  }
+  if (!ary.AppendElements(copy))
+    return false;
+  uint32_t cap = ary.Capacity();
+  ary.RemoveElementsAt(copy.Length(), copy.Length());
+  ary.Compact();
+  if (ary.Capacity() == cap)
+    return false;
+
+  ary.Clear();
+  if (ary.IndexOf(extra) != UINT32_MAX)
+    return false;
+  if (ary.LastIndexOf(extra) != UINT32_MAX)
+    return false;
+
+  ary.Clear();
+  if (!ary.IsEmpty() || ary.Elements() == nullptr)
+    return false;
+  if (!(ary == nsTArray<ElementType>()))
+    return false;
+  if (ary == copy)
+    return false;
+  if (ary.SafeElementAt(0, extra) != extra ||
+      ary.SafeElementAt(10, extra) != extra)
+    return false;
+
+  ary = copy;
+  if (!(ary == copy))
+    return false;
+  for (i = 0; i < copy.Length(); ++i) {
+    if (ary[i] != copy[i])
+      return false;
+  }
+
+  if (!ary.InsertElementsAt(0, copy))
+    return false;
+  if (ary == copy)
+    return false;
+  ary.RemoveElementsAt(0, copy.Length());
+  for (i = 0; i < copy.Length(); ++i) {
+    if (ary[i] != copy[i])
+      return false;
+  }
+
+  // These shouldn't crash!
+  nsTArray<ElementType> empty;
+  ary.AppendElements(reinterpret_cast<ElementType *>(0), 0);
+  ary.AppendElements(empty);
+
+  // See bug 324981
+  ary.RemoveElement(extra);
+  ary.RemoveElement(extra);
+
+  return true;
+}
+
+static bool test_int_array() {
+  int data[] = {4,6,8,2,4,1,5,7,3};
+  return test_basic_array(data, ArrayLength(data), int(14));
+}
+
+static bool test_int64_array() {
+  int64_t data[] = {4,6,8,2,4,1,5,7,3};
+  return test_basic_array(data, ArrayLength(data), int64_t(14));
+}
+
+static bool test_char_array() {
+  char data[] = {4,6,8,2,4,1,5,7,3};
+  return test_basic_array(data, ArrayLength(data), char(14));
+}
+
+static bool test_uint32_array() {
+  uint32_t data[] = {4,6,8,2,4,1,5,7,3};
+  return test_basic_array(data, ArrayLength(data), uint32_t(14));
+}
+
+//----
+
+class Object {
+  public:
+    Object() : mNum(0) {
+    }
+    Object(const char *str, uint32_t num) : mStr(str), mNum(num) {
+    }
+    Object(const Object& other) : mStr(other.mStr), mNum(other.mNum) {
+    }
+    ~Object() {}
+
+    Object& operator=(const Object& other) {
+      mStr = other.mStr;
+      mNum = other.mNum;
+      return *this;
+    }
+
+    bool operator==(const Object& other) const {
+      return mStr == other.mStr && mNum == other.mNum;
+    }
+
+    bool operator<(const Object& other) const {
+      // sort based on mStr only
+      return mStr.Compare(other.mStr) < 0;
+    }
+
+    const char *Str() const { return mStr.get(); }
+    uint32_t Num() const { return mNum; }
+
+  private:
+    nsCString mStr;
+    uint32_t  mNum;
+};
+
+static bool test_object_array() {
+  nsTArray<Object> objArray;
+  const char kdata[] = "hello world";
+  uint32_t i;
+  for (i = 0; i < ArrayLength(kdata); ++i) {
+    char x[] = {kdata[i],'\0'};
+    if (!objArray.AppendElement(Object(x, i)))
+      return false;
+  }
+  for (i = 0; i < ArrayLength(kdata); ++i) {
+    if (objArray[i].Str()[0] != kdata[i])
+      return false;
+    if (objArray[i].Num() != i)
+      return false;
+  }
+  objArray.Sort();
+  const char ksorted[] = "\0 dehllloorw";
+  for (i = 0; i < ArrayLength(kdata)-1; ++i) {
+    if (objArray[i].Str()[0] != ksorted[i])
+      return false;
+  }
+  return true;
+}
+
+// nsTArray<nsAutoPtr<T>> is not supported
+#if 0
+static bool test_autoptr_array() {
+  nsTArray< nsAutoPtr<Object> > objArray;
+  const char kdata[] = "hello world";
+  for (uint32_t i = 0; i < ArrayLength(kdata); ++i) {
+    char x[] = {kdata[i],'\0'};
+    nsAutoPtr<Object> obj(new Object(x,i));
+    if (!objArray.AppendElement(obj))  // XXX does not call copy-constructor for nsAutoPtr!!!
+      return false;
+    if (obj.get() == nullptr)
+      return false;
+    obj.forget();  // the array now owns the reference
+  }
+  for (uint32_t i = 0; i < ArrayLength(kdata); ++i) {
+    if (objArray[i]->Str()[0] != kdata[i])
+      return false;
+    if (objArray[i]->Num() != i)
+      return false;
+  }
+  return true;
+}
+#endif
+
+//----
+
+static bool test_string_array() {
+  nsTArray<nsCString> strArray;
+  const char kdata[] = "hello world";
+  uint32_t i;
+  for (i = 0; i < ArrayLength(kdata); ++i) {
+    nsCString str;
+    str.Assign(kdata[i]);
+    if (!strArray.AppendElement(str))
+      return false;
+  }
+  for (i = 0; i < ArrayLength(kdata); ++i) {
+    if (strArray[i].CharAt(0) != kdata[i])
+      return false;
+  }
+
+  const char kextra[] = "foo bar";
+  uint32_t oldLen = strArray.Length();
+  if (!strArray.AppendElement(kextra))
+    return false;
+  strArray.RemoveElement(kextra);
+  if (oldLen != strArray.Length())
+    return false;
+
+  if (strArray.IndexOf("e") != 1)
+    return false;
+
+  strArray.Sort();
+  const char ksorted[] = "\0 dehllloorw";
+  for (i = ArrayLength(kdata); i--; ) {
+    if (strArray[i].CharAt(0) != ksorted[i])
+      return false;
+    if (i > 0 && strArray[i] == strArray[i - 1])
+      strArray.RemoveElementAt(i);
+  }
+  for (i = 0; i < strArray.Length(); ++i) {
+    if (strArray.BinaryIndexOf(strArray[i]) != i)
+      return false;
+  }
+  if (strArray.BinaryIndexOf(EmptyCString()) != strArray.NoIndex)
+    return false;
+
+  nsCString rawArray[MOZ_ARRAY_LENGTH(kdata) - 1];
+  for (i = 0; i < ArrayLength(rawArray); ++i)
+    rawArray[i].Assign(kdata + i);  // substrings of kdata
+  return test_basic_array(rawArray, ArrayLength(rawArray),
+                          nsCString("foopy"));
+}
+
+//----
+
+typedef nsCOMPtr<nsIFile> FilePointer;
+
+class nsFileNameComparator {
+  public:
+    bool Equals(const FilePointer &a, const char *b) const {
+      nsAutoCString name;
+      a->GetNativeLeafName(name);
+      return name.Equals(b);
+    }
+};
+
+static bool test_comptr_array() {
+  FilePointer tmpDir;
+  NS_GetSpecialDirectory(NS_OS_TEMP_DIR, getter_AddRefs(tmpDir));
+  if (!tmpDir)
+    return false;
+  const char *kNames[] = {
+    "foo.txt", "bar.html", "baz.gif"
+  };
+  nsTArray<FilePointer> fileArray;
+  uint32_t i;
+  for (i = 0; i < ArrayLength(kNames); ++i) {
+    FilePointer f;
+    tmpDir->Clone(getter_AddRefs(f));
+    if (!f)
+      return false;
+    if (NS_FAILED(f->AppendNative(nsDependentCString(kNames[i]))))
+      return false;
+    fileArray.AppendElement(f);
+  }
+
+  if (fileArray.IndexOf(kNames[1], 0, nsFileNameComparator()) != 1)
+    return false;
+
+  // It's unclear what 'operator<' means for nsCOMPtr, but whatever...
+  return test_basic_array(fileArray.Elements(), fileArray.Length(), 
+                          tmpDir);
+}
+
+//----
+
+class RefcountedObject {
+  public:
+    RefcountedObject() : rc(0) {}
+    void AddRef() {
+      ++rc;
+    }
+    void Release() {
+      if (--rc == 0)
+        delete this;
+    }
+    ~RefcountedObject() {}
+  private:
+    int32_t rc;
+};
+
+static bool test_refptr_array() {
+  bool rv = true;
+
+  nsTArray< nsRefPtr<RefcountedObject> > objArray;
+
+  RefcountedObject *a = new RefcountedObject(); a->AddRef();
+  RefcountedObject *b = new RefcountedObject(); b->AddRef();
+  RefcountedObject *c = new RefcountedObject(); c->AddRef();
+
+  objArray.AppendElement(a);
+  objArray.AppendElement(b);
+  objArray.AppendElement(c);
+
+  if (objArray.IndexOf(b) != 1)
+    rv = false;
+
+  a->Release();
+  b->Release();
+  c->Release();
+  return rv;
+}
+
+//----
+
+static bool test_ptrarray() {
+  nsTArray<uint32_t*> ary;
+  if (ary.SafeElementAt(0) != nullptr)
+    return false;
+  if (ary.SafeElementAt(1000) != nullptr)
+    return false;
+  uint32_t a = 10;
+  ary.AppendElement(&a);
+  if (*ary[0] != a)
+    return false;
+  if (*ary.SafeElementAt(0) != a)
+    return false;
+
+  nsTArray<const uint32_t*> cary;
+  if (cary.SafeElementAt(0) != nullptr)
+    return false;
+  if (cary.SafeElementAt(1000) != nullptr)
+    return false;
+  const uint32_t b = 14;
+  cary.AppendElement(&a);
+  cary.AppendElement(&b);
+  if (*cary[0] != a || *cary[1] != b)
+    return false;
+  if (*cary.SafeElementAt(0) != a || *cary.SafeElementAt(1) != b)
+    return false;
+
+  return true;
+}
+
+//----
+
+// This test relies too heavily on the existence of DebugGetHeader to be
+// useful in non-debug builds.
+#ifdef DEBUG
+static bool test_autoarray() {
+  uint32_t data[] = {4,6,8,2,4,1,5,7,3};
+  nsAutoTArray<uint32_t, MOZ_ARRAY_LENGTH(data)> array;
+
+  void* hdr = array.DebugGetHeader();
+  if (hdr == nsTArray<uint32_t>().DebugGetHeader())
+    return false;
+  if (hdr == nsAutoTArray<uint32_t, MOZ_ARRAY_LENGTH(data)>().DebugGetHeader())
+    return false;
+
+  array.AppendElement(1u);
+  if (hdr != array.DebugGetHeader())
+    return false;
+
+  array.RemoveElement(1u);
+  array.AppendElements(data, ArrayLength(data));
+  if (hdr != array.DebugGetHeader())
+    return false;
+
+  array.AppendElement(2u);
+  if (hdr == array.DebugGetHeader())
+    return false;
+
+  array.Clear();
+  array.Compact();
+  if (hdr != array.DebugGetHeader())
+    return false;
+  array.AppendElements(data, ArrayLength(data));
+  if (hdr != array.DebugGetHeader())
+    return false;
+
+  nsTArray<uint32_t> array2;
+  void* emptyHdr = array2.DebugGetHeader();
+  array.SwapElements(array2);
+  if (emptyHdr == array.DebugGetHeader())
+    return false;
+  if (hdr == array2.DebugGetHeader())
+    return false;
+  uint32_t i;
+  for (i = 0; i < ArrayLength(data); ++i) {
+    if (array2[i] != data[i])
+      return false;
+  }
+  if (!array.IsEmpty())
+    return false;
+
+  array.Compact();
+  array.AppendElements(data, ArrayLength(data));
+  uint32_t data3[] = {5, 7, 11};
+  nsAutoTArray<uint32_t, MOZ_ARRAY_LENGTH(data3)> array3;
+  array3.AppendElements(data3, ArrayLength(data3));  
+  array.SwapElements(array3);
+  for (i = 0; i < ArrayLength(data); ++i) {
+    if (array3[i] != data[i])
+      return false;
+  }
+  for (i = 0; i < ArrayLength(data3); ++i) {
+    if (array[i] != data3[i])
+      return false;
+  }
+
+  return true;
+}
+#endif
+
+//----
+
+// IndexOf used to potentially scan beyond the end of the array.  Test for
+// this incorrect behavior by adding a value (5), removing it, then seeing
+// if IndexOf finds it.
+static bool test_indexof() {
+  nsTArray<int> array;
+  array.AppendElement(0);
+  // add and remove the 5
+  array.AppendElement(5);
+  array.RemoveElementAt(1);
+  // we should not find the 5!
+  return array.IndexOf(5, 1) == array.NoIndex;
+}
+
+//----
+
+template <class Array>
+static bool is_heap(const Array& ary, uint32_t len) {
+  uint32_t index = 1;
+  while (index < len) {
+    if (ary[index] > ary[(index - 1) >> 1])
+      return false;
+    index++;
+  }
+  return true;
+} 
+
+static bool test_heap() {
+  const int data[] = {4,6,8,2,4,1,5,7,3};
+  nsTArray<int> ary;
+  ary.AppendElements(data, ArrayLength(data));
+  // make a heap and make sure it's a heap
+  ary.MakeHeap();
+  if (!is_heap(ary, ArrayLength(data)))
+    return false;
+  // pop the root and make sure it's still a heap
+  int root = ary[0];
+  ary.PopHeap();
+  if (!is_heap(ary, ArrayLength(data) - 1))
+    return false;
+  // push the previously poped value back on and make sure it's still a heap
+  ary.PushHeap(root);
+  if (!is_heap(ary, ArrayLength(data)))
+    return false;
+  // make sure the heap looks like what we expect
+  const int expected_data[] = {8,7,5,6,4,1,4,2,3};
+  uint32_t index;
+  for (index = 0; index < ArrayLength(data); index++)
+    if (ary[index] != expected_data[index])
+      return false;
+  return true;
+}
+
+//----
+
+// An array |arr| is using its auto buffer if |&arr < arr.Elements()| and
+// |arr.Elements() - &arr| is small.
+
+#define IS_USING_AUTO(arr) \
+  ((uintptr_t) &(arr) < (uintptr_t) arr.Elements() && \
+   ((ptrdiff_t)arr.Elements() - (ptrdiff_t)&arr) <= 16)
+
+#define CHECK_IS_USING_AUTO(arr) \
+  do {                                                    \
+    if (!(IS_USING_AUTO(arr))) {                          \
+      printf("%s:%d CHECK_IS_USING_AUTO(%s) failed.\n",   \
+             __FILE__, __LINE__, #arr);                   \
+      return false;                                    \
+    }                                                     \
+  } while(0)
+
+#define CHECK_NOT_USING_AUTO(arr) \
+  do {                                                    \
+    if (IS_USING_AUTO(arr)) {                             \
+      printf("%s:%d CHECK_NOT_USING_AUTO(%s) failed.\n",  \
+             __FILE__, __LINE__, #arr);                   \
+      return false;                                    \
+    }                                                     \
+  } while(0)
+
+#define CHECK_USES_SHARED_EMPTY_HDR(arr) \
+  do {                                                    \
+    nsTArray<int> _empty;                                 \
+    if (_empty.Elements() != arr.Elements()) {            \
+      printf("%s:%d CHECK_USES_EMPTY_HDR(%s) failed.\n",  \
+             __FILE__, __LINE__, #arr);                   \
+      return false;                                    \
+    }                                                     \
+  } while(0)
+
+#define CHECK_EQ_INT(actual, expected) \
+  do {                                                                       \
+    if ((actual) != (expected)) {                                            \
+      printf("%s:%d CHECK_EQ_INT(%s=%u, %s=%u) failed.\n",                   \
+             __FILE__, __LINE__, #actual, (actual), #expected, (expected));  \
+      return false;                                                       \
+    }                                                                        \
+  } while(0)
+
+#define CHECK_ARRAY(arr, data) \
+  do {                                                          \
+    CHECK_EQ_INT((arr).Length(), (uint32_t)ArrayLength(data));  \
+    for (uint32_t _i = 0; _i < ArrayLength(data); _i++) {       \
+      CHECK_EQ_INT((arr)[_i], (data)[_i]);                      \
+    }                                                           \
+  } while(0)
+
+static bool test_swap() {
+  // Test nsTArray::SwapElements.  Unfortunately there are many cases.
+  int data1[] = {8, 6, 7, 5};
+  int data2[] = {3, 0, 9};
+
+  // Swap two auto arrays.
+  {
+    nsAutoTArray<int, 8> a;
+    nsAutoTArray<int, 6> b;
+
+    a.AppendElements(data1, ArrayLength(data1));
+    b.AppendElements(data2, ArrayLength(data2));
+    CHECK_IS_USING_AUTO(a);
+    CHECK_IS_USING_AUTO(b);
+
+    a.SwapElements(b);
+
+    CHECK_IS_USING_AUTO(a);
+    CHECK_IS_USING_AUTO(b);
+    CHECK_ARRAY(a, data2);
+    CHECK_ARRAY(b, data1);
+  }
+
+  // Swap two auto arrays -- one whose data lives on the heap, the other whose
+  // data lives on the stack -- which each fits into the other's auto storage.
+  {
+    nsAutoTArray<int, 3> a;
+    nsAutoTArray<int, 3> b;
+
+    a.AppendElements(data1, ArrayLength(data1));
+    a.RemoveElementAt(3);
+    b.AppendElements(data2, ArrayLength(data2));
+
+    // Here and elsewhere, we assert that if we start with an auto array
+    // capable of storing N elements, we store N+1 elements into the array, and
+    // then we remove one element, that array is still not using its auto
+    // buffer.
+    //
+    // This isn't at all required by the TArray API. It would be fine if, when
+    // we shrink back to N elements, the TArray frees its heap storage and goes
+    // back to using its stack storage.  But we assert here as a check that the
+    // test does what we expect.  If the TArray implementation changes, just
+    // change the failing assertions.
+    CHECK_NOT_USING_AUTO(a);
+
+    // This check had better not change, though.
+    CHECK_IS_USING_AUTO(b);
+
+    a.SwapElements(b);
+
+    CHECK_IS_USING_AUTO(b);
+    CHECK_ARRAY(a, data2);
+    int expectedB[] = {8, 6, 7};
+    CHECK_ARRAY(b, expectedB);
+  }
+
+  // Swap two auto arrays which are using heap storage such that one fits into
+  // the other's auto storage, but the other needs to stay on the heap.
+  {
+    nsAutoTArray<int, 3> a;
+    nsAutoTArray<int, 2> b;
+    a.AppendElements(data1, ArrayLength(data1));
+    a.RemoveElementAt(3);
+
+    b.AppendElements(data2, ArrayLength(data2));
+    b.RemoveElementAt(2);
+
+    CHECK_NOT_USING_AUTO(a);
+    CHECK_NOT_USING_AUTO(b);
+
+    a.SwapElements(b);
+
+    CHECK_NOT_USING_AUTO(b);
+
+    int expected1[] = {3, 0};
+    int expected2[] = {8, 6, 7};
+
+    CHECK_ARRAY(a, expected1);
+    CHECK_ARRAY(b, expected2);
+  }
+
+  // Swap two arrays, neither of which fits into the other's auto-storage.
+  {
+    nsAutoTArray<int, 1> a;
+    nsAutoTArray<int, 3> b;
+
+    a.AppendElements(data1, ArrayLength(data1));
+    b.AppendElements(data2, ArrayLength(data2));
+
+    a.SwapElements(b);
+
+    CHECK_ARRAY(a, data2);
+    CHECK_ARRAY(b, data1);
+  }
+
+  // Swap an empty nsTArray with a non-empty nsAutoTArray.
+  {
+    nsTArray<int> a;
+    nsAutoTArray<int, 3> b;
+
+    b.AppendElements(data2, ArrayLength(data2));
+    CHECK_IS_USING_AUTO(b);
+
+    a.SwapElements(b);
+
+    CHECK_ARRAY(a, data2);
+    CHECK_EQ_INT(b.Length(), 0);
+    CHECK_IS_USING_AUTO(b);
+  }
+
+  // Swap two big auto arrays.
+  {
+    const unsigned size = 8192;
+    nsAutoTArray<unsigned, size> a;
+    nsAutoTArray<unsigned, size> b;
+
+    for (unsigned i = 0; i < size; i++) {
+      a.AppendElement(i);
+      b.AppendElement(i + 1);
+    }
+
+    CHECK_IS_USING_AUTO(a);
+    CHECK_IS_USING_AUTO(b);
+
+    a.SwapElements(b);
+
+    CHECK_IS_USING_AUTO(a);
+    CHECK_IS_USING_AUTO(b);
+
+    CHECK_EQ_INT(a.Length(), size);
+    CHECK_EQ_INT(b.Length(), size);
+
+    for (unsigned i = 0; i < size; i++) {
+      CHECK_EQ_INT(a[i], i + 1);
+      CHECK_EQ_INT(b[i], i);
+    }
+  }
+
+  // Swap two arrays and make sure that their capacities don't increase
+  // unnecessarily.
+  {
+    nsTArray<int> a;
+    nsTArray<int> b;
+    b.AppendElements(data2, ArrayLength(data2));
+
+    CHECK_EQ_INT(a.Capacity(), 0);
+    uint32_t bCapacity = b.Capacity();
+
+    a.SwapElements(b);
+
+    // Make sure that we didn't increase the capacity of either array.
+    CHECK_ARRAY(a, data2);
+    CHECK_EQ_INT(b.Length(), 0);
+    CHECK_EQ_INT(b.Capacity(), 0);
+    CHECK_EQ_INT(a.Capacity(), bCapacity);
+  }
+
+  // Swap an auto array with a TArray, then clear the auto array and make sure
+  // it doesn't forget the fact that it has an auto buffer.
+  {
+    nsTArray<int> a;
+    nsAutoTArray<int, 3> b;
+
+    a.AppendElements(data1, ArrayLength(data1));
+
+    a.SwapElements(b);
+
+    CHECK_EQ_INT(a.Length(), 0);
+    CHECK_ARRAY(b, data1);
+
+    b.Clear();
+
+    CHECK_USES_SHARED_EMPTY_HDR(a);
+    CHECK_IS_USING_AUTO(b);
+  }
+
+  // Same thing as the previous test, but with more auto arrays.
+  {
+    nsAutoTArray<int, 16> a;
+    nsAutoTArray<int, 3> b;
+
+    a.AppendElements(data1, ArrayLength(data1));
+
+    a.SwapElements(b);
+
+    CHECK_EQ_INT(a.Length(), 0);
+    CHECK_ARRAY(b, data1);
+
+    b.Clear();
+
+    CHECK_IS_USING_AUTO(a);
+    CHECK_IS_USING_AUTO(b);
+  }
+
+  // Swap an empty nsTArray and an empty nsAutoTArray.
+  {
+    nsAutoTArray<int, 8> a;
+    nsTArray<int> b;
+
+    a.SwapElements(b);
+
+    CHECK_IS_USING_AUTO(a);
+    CHECK_NOT_USING_AUTO(b);
+    CHECK_EQ_INT(a.Length(), 0);
+    CHECK_EQ_INT(b.Length(), 0);
+  }
+
+  // Swap empty auto array with non-empty nsAutoTArray using malloc'ed storage.
+  // I promise, all these tests have a point.
+  {
+    nsAutoTArray<int, 2> a;
+    nsAutoTArray<int, 1> b;
+
+    a.AppendElements(data1, ArrayLength(data1));
+
+    a.SwapElements(b);
+
+    CHECK_IS_USING_AUTO(a);
+    CHECK_NOT_USING_AUTO(b);
+    CHECK_ARRAY(b, data1);
+    CHECK_EQ_INT(a.Length(), 0);
+  }
+
+  return true;
+}
+
+static bool test_fallible()
+{
+  // Test that FallibleTArray works properly; that is, it never OOMs, but
+  // instead eventually returns false.
+  //
+  // This test is only meaningful on 32-bit systems.  On a 64-bit system, we
+  // might never OOM.
+  if (sizeof(void*) > 4) {
+    return true;
+  }
+
+  // Allocate a bunch of 128MB arrays.  Larger allocations will fail on some
+  // platforms without actually hitting OOM.
+  //
+  // 36 * 128MB > 4GB, so we should definitely OOM by the 36th array.
+  const unsigned numArrays = 36;
+  FallibleTArray<char> arrays[numArrays];
+  for (uint32_t i = 0; i < numArrays; i++) {
+    bool success = arrays[i].SetCapacity(128 * 1024 * 1024);
+    if (!success) {
+      // We got our OOM.  Check that it didn't come too early.
+      if (i < 8) {
+        printf("test_fallible: Got OOM on iteration %d.  Too early!\n", i);
+        return false;
+      }
+      return true;
+    }
+  }
+
+  // No OOM?  That's...weird.
+  printf("test_fallible: Didn't OOM or crash?  nsTArray::SetCapacity "
+         "must be lying.\n");
+  return false;
+}
+
+static bool test_conversion_operator() {
+  FallibleTArray<int> f;
+  const FallibleTArray<int> fconst;
+  AutoFallibleTArray<int, 8> fauto;
+  const AutoFallibleTArray<int, 8> fautoconst;
+
+  InfallibleTArray<int> i;
+  const InfallibleTArray<int> iconst;
+  AutoInfallibleTArray<int, 8> iauto;
+  const AutoInfallibleTArray<int, 8> iautoconst;
+
+  nsTArray<int> t;
+  const nsTArray<int> tconst;
+  nsAutoTArray<int, 8> tauto;
+  const nsAutoTArray<int, 8> tautoconst;
+
+#define CHECK_ARRAY_CAST(type)                                 \
+  do {                                                         \
+    const type<int>& z1 = f;                                   \
+    if ((void*)&z1 != (void*)&f) return false;                 \
+    const type<int>& z2 = fconst;                              \
+    if ((void*)&z2 != (void*)&fconst) return false;            \
+    const type<int>& z3 = fauto;                               \
+    if ((void*)&z3 != (void*)&fauto) return false;             \
+    const type<int>& z4 = fautoconst;                          \
+    if ((void*)&z4 != (void*)&fautoconst) return false;        \
+    const type<int>& z5 = i;                                   \
+    if ((void*)&z5 != (void*)&i) return false;                 \
+    const type<int>& z6 = iconst;                              \
+    if ((void*)&z6 != (void*)&iconst) return false;            \
+    const type<int>& z7 = iauto;                               \
+    if ((void*)&z7 != (void*)&iauto) return false;             \
+    const type<int>& z8 = iautoconst;                          \
+    if ((void*)&z8 != (void*)&iautoconst) return false;        \
+    const type<int>& z9 = t;                                   \
+    if ((void*)&z9 != (void*)&t) return false;                 \
+    const type<int>& z10 = tconst;                             \
+    if ((void*)&z10 != (void*)&tconst) return false;           \
+    const type<int>& z11 = tauto;                              \
+    if ((void*)&z11 != (void*)&tauto) return false;            \
+    const type<int>& z12 = tautoconst;                         \
+    if ((void*)&z12 != (void*)&tautoconst) return false;       \
+  } while (0)
+
+  CHECK_ARRAY_CAST(FallibleTArray);
+  CHECK_ARRAY_CAST(InfallibleTArray);
+  CHECK_ARRAY_CAST(nsTArray);
+
+#undef CHECK_ARRAY_CAST
+
+  return true;
+}
+
+template<class T>
+struct BufAccessor : public T
+{
+  void* GetHdr() { return T::mHdr; }
+};
+
+static bool test_SetLengthAndRetainStorage_no_ctor() {
+  // 1050 because sizeof(int)*1050 is more than a page typically.
+  const int N = 1050;
+  FallibleTArray<int> f;
+  AutoFallibleTArray<int, N> fauto;
+
+  InfallibleTArray<int> i;
+  AutoInfallibleTArray<int, N> iauto;
+
+  nsTArray<int> t;
+  nsAutoTArray<int, N> tauto;
+
+#define LPAREN (
+#define RPAREN )
+#define FOR_EACH(pre, post)                                    \
+  do {                                                         \
+    pre f post;                                                \
+    pre fauto post;                                            \
+    pre i post;                                                \
+    pre iauto post;                                            \
+    pre t post;                                                \
+    pre tauto post;                                            \
+  } while (0)
+  
+  // Setup test arrays.
+  FOR_EACH(;, .SetLength(N));
+  for (int n = 0; n < N; ++n) {
+    FOR_EACH(;, [n] = n);
+  }
+
+  void* initial_Hdrs[] = {
+    static_cast<BufAccessor<FallibleTArray<int> >&>(f).GetHdr(),
+    static_cast<BufAccessor<AutoFallibleTArray<int, N> >&>(fauto).GetHdr(),
+    static_cast<BufAccessor<InfallibleTArray<int> >&>(i).GetHdr(),
+    static_cast<BufAccessor<AutoInfallibleTArray<int, N> >&>(iauto).GetHdr(),
+    static_cast<BufAccessor<nsTArray<int> >&>(t).GetHdr(),
+    static_cast<BufAccessor<nsAutoTArray<int, N> >&>(tauto).GetHdr(),
+    nullptr
+  };
+
+  // SetLengthAndRetainStorage(n), should NOT overwrite memory when T hasn't
+  // a default constructor.
+  FOR_EACH(;, .SetLengthAndRetainStorage(8));
+  FOR_EACH(;, .SetLengthAndRetainStorage(12));
+  for (int n = 0; n < 12; ++n) {
+    FOR_EACH(if LPAREN, [n] != n RPAREN return false);
+  }
+  FOR_EACH(;, .SetLengthAndRetainStorage(0));
+  FOR_EACH(;, .SetLengthAndRetainStorage(N));
+  for (int n = 0; n < N; ++n) {
+    FOR_EACH(if LPAREN, [n] != n RPAREN return false);
+  }
+
+  void* current_Hdrs[] = {
+    static_cast<BufAccessor<FallibleTArray<int> >&>(f).GetHdr(),
+    static_cast<BufAccessor<AutoFallibleTArray<int, N> >&>(fauto).GetHdr(),
+    static_cast<BufAccessor<InfallibleTArray<int> >&>(i).GetHdr(),
+    static_cast<BufAccessor<AutoInfallibleTArray<int, N> >&>(iauto).GetHdr(),
+    static_cast<BufAccessor<nsTArray<int> >&>(t).GetHdr(),
+    static_cast<BufAccessor<nsAutoTArray<int, N> >&>(tauto).GetHdr(),
+    nullptr
+  };
+
+  // SetLengthAndRetainStorage(n) should NOT have reallocated the internal
+  // memory.
+  if (sizeof(initial_Hdrs) != sizeof(current_Hdrs)) return false;
+  for (size_t n = 0; n < sizeof(current_Hdrs) / sizeof(current_Hdrs[0]); ++n) {
+    if (current_Hdrs[n] != initial_Hdrs[n]) {
+      return false;
+    }
+  }
+
+
+#undef FOR_EACH
+#undef LPAREN
+#undef RPAREN
+
+  return true;
+}
+
+//----
+
+typedef bool (*TestFunc)();
+#define DECL_TEST(name) { #name, name }
+
+static const struct Test {
+  const char* name;
+  TestFunc    func;
+} tests[] = {
+  DECL_TEST(test_int_array),
+  DECL_TEST(test_int64_array),
+  DECL_TEST(test_char_array),
+  DECL_TEST(test_uint32_array),
+  DECL_TEST(test_object_array),
+  DECL_TEST(test_string_array),
+  DECL_TEST(test_comptr_array),
+  DECL_TEST(test_refptr_array),
+  DECL_TEST(test_ptrarray),
+#ifdef DEBUG
+  DECL_TEST(test_autoarray),
+#endif
+  DECL_TEST(test_indexof),
+  DECL_TEST(test_heap),
+  DECL_TEST(test_swap),
+  DECL_TEST(test_fallible),
+  DECL_TEST(test_conversion_operator),
+  DECL_TEST(test_SetLengthAndRetainStorage_no_ctor),
+  { nullptr, nullptr }
+};
+
+}
+
+using namespace TestTArray;
+
+int main(int argc, char **argv) {
+  int count = 1;
+  if (argc > 1)
+    count = atoi(argv[1]);
+
+  if (NS_FAILED(NS_InitXPCOM2(nullptr, nullptr, nullptr)))
+    return -1;
+
+  bool success = true;
+  while (count--) {
+    for (const Test* t = tests; t->name != nullptr; ++t) {
+      bool test_result = t->func();
+      printf("%25s : %s\n", t->name, test_result ? "SUCCESS" : "FAILURE");
+      if (!test_result)
+        success = false;
+    }
+  }
+  
+  NS_ShutdownXPCOM(nullptr);
+  return success ? 0 : -1;
+}