WriteData and BeginWriteData should fail if length is

negative.

Add a unit test for WriteData(NULL, 0).

R=darin
BUG=none
TEST=new unit test should pass
Review URL: http://codereview.chromium.org/159310

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@21886 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 17 insertions, 4 deletions

diff --git a/base/pickle.cc b/base/pickle.cc
index c3df8bc..e491832 100644
--- a/base/pickle.cc
+++ b/base/pickle.cc
@@ -322,15 +322,15 @@ bool Pickle::WriteString16(const string16& value) {
 }
 
 bool Pickle::WriteData(const char* data, int length) {
-  return WriteInt(length) && WriteBytes(data, length);
+  return length >= 0 && WriteInt(length) && WriteBytes(data, length);
 }
 
 char* Pickle::BeginWriteData(int length) {
   DCHECK_EQ(variable_buffer_offset_, 0U) <<
     "There can only be one variable buffer in a Pickle";
 
-  if (!WriteInt(length))
-    return false;
+  if (length < 0 || !WriteInt(length))
+    return NULL;
 
   char *data_ptr = BeginWrite(length);
   if (!data_ptr)
diff --git a/base/pickle_unittest.cc b/base/pickle_unittest.cc
index 1ddbd22..1a98cd2 100644
--- a/base/pickle_unittest.cc
+++ b/base/pickle_unittest.cc
@@ -13,7 +13,7 @@
 namespace {
 
 const int testint = 2093847192;
-const std::string teststr("Hello world"); // note non-aligned string length
+const std::string teststr("Hello world");  // note non-aligned string length
 const std::wstring testwstr(L"Hello, world");
 const char testdata[] = "AAA\0BBB\0";
 const int testdatalen = arraysize(testdata) - 1;
@@ -246,3 +246,16 @@ TEST(PickleTest, EvilLengths) {
   EXPECT_FALSE(big_len.ReadWString(&iter, &wstr));
 }
 
+// Check we can write zero bytes of data and 'data' can be NULL.
+TEST(PickleTest, ZeroLength) {
+  Pickle pickle;
+  EXPECT_TRUE(pickle.WriteData(NULL, 0));
+
+  void* iter = NULL;
+  const char* outdata;
+  int outdatalen;
+  EXPECT_TRUE(pickle.ReadData(&iter, &outdata, &outdatalen));
+  EXPECT_EQ(0, outdatalen);
+  // We can't assert that outdata is NULL.
+}
+