[PATCH] shcore: Return failure on Read past end of memory stream.

[Daniel Lehman]

Signed-off-by: Daniel Lehman 
---
 dlls/shcore/main.c           | 18 ++++++------
 dlls/shlwapi/tests/istream.c | 55 ++++++++++++++++++++++++++++++++++--
 2 files changed, 62 insertions(+), 11 deletions(-)

diff --git a/dlls/shcore/main.c b/dlls/shcore/main.c
index dc782e8be08..d5fce76eade 100644
--- a/dlls/shcore/main.c
+++ b/dlls/shcore/main.c
@@ -603,17 +603,19 @@ static HRESULT WINAPI memstream_Read(IStream *iface, void *buff, ULONG buff_size
     TRACE("(%p)->(%p, %u, %p)\n", stream, buff, buff_size, read_len);

if (stream->u.mem.position >= stream->u.mem.length)
-        length = 0;
-    else
-        length = stream->u.mem.length - stream->u.mem.position;
-
-    length = buff_size > length ? length : buff_size;
-    if (length != 0) /* not at end of buffer and we want to read something */
     {
-        memmove(buff, stream->u.mem.buffer + stream->u.mem.position, length);
-        stream->u.mem.position += length; /* adjust pointer */
+        if (read_len)
+            *read_len = 0;
+        return S_FALSE;
     }

+    length = stream->u.mem.length - stream->u.mem.position;
+    if (buff_size < length)
+        length = buff_size;
+
+    memmove(buff, stream->u.mem.buffer + stream->u.mem.position, length);
+    stream->u.mem.position += length;
+
     if (read_len)
         *read_len = length;

diff --git a/dlls/shlwapi/tests/istream.c b/dlls/shlwapi/tests/istream.c
index d3e7dbb8810..84957ac8cd1 100644
--- a/dlls/shlwapi/tests/istream.c
+++ b/dlls/shlwapi/tests/istream.c
@@ -736,8 +736,10 @@ static void test_SHCreateMemStream(void)
 {
     static const BYTE initial[10];
     IStream *stream, *stream2;
+    LARGE_INTEGER off;
     IUnknown *unk;
     char buff[10];
+    ULONG i, num;
     HRESULT hr;

stream = SHCreateMemStream(initial, 0);
@@ -756,9 +758,56 @@ static void test_SHCreateMemStream(void)
     if (unk)
         IUnknown_Release(unk);

-    hr = IStream_Read(stream, buff, sizeof(buff), NULL);
-todo_wine
-    ok(hr == S_FALSE || broken(hr == S_OK) /* WinXP */, "Unexpected hr %#x.\n", hr);
+    num = ~0;
+    hr = IStream_Read(stream, buff, sizeof(buff), &num);
+    ok(hr == S_FALSE, "Unexpected hr %#x.\n", hr);
+    ok(num == 0, "expected 0, got 0x%08x\n", num);
+
+    num = ~0;
+    memset(buff, 0x55, sizeof(buff));
+    hr = IStream_Write(stream, buff, sizeof(buff), &num);
+    ok(hr == S_OK, "Failed to write, hr %#x.\n", hr);
+    ok(num == sizeof(buff), "expected %u, got %u\n", sizeof(buff), num);
+
+    off.QuadPart = 0;
+    hr = IStream_Seek(stream, off, STREAM_SEEK_SET, NULL);
+    ok(hr == S_OK, "Failed to seek, hr %#x.\n", hr);
+
+    num = ~0;
+    memset(buff, 0, sizeof(buff));
+    hr = IStream_Read(stream, buff, sizeof(buff), &num);
+    ok(hr == S_OK, "Failed to read, hr %#x.\n", hr);
+    ok(num == sizeof(buff), "expected %u, got %u\n", sizeof(buff), num);
+    for (i = 0; i < ARRAY_SIZE(buff); i++)
+        ok(buff[i] == 0x55, "expected 0x55, got 0x%02x at %u\n", buff[i], i);
+
+    num = ~0;
+    hr = IStream_Read(stream, buff, sizeof(buff), &num);
+    ok(hr == S_FALSE, "Unexpected hr %#x.\n", hr);
+    ok(num == 0, "expected 0, got 0x%08x\n", num);
+
+    num = ~0;
+    memset(buff, 0x11, sizeof(buff));
+    hr = IStream_Write(stream, buff, sizeof(buff), &num);
+    ok(hr == S_OK, "Failed to write, hr %#x.\n", hr);
+    ok(num == sizeof(buff), "expected %u, got %u\n", sizeof(buff), num);
+
+    off.QuadPart = -sizeof(buff);
+    hr = IStream_Seek(stream, off, STREAM_SEEK_CUR, NULL);
+    ok(hr == S_OK, "Failed to seek, hr %#x.\n", hr);
+
+    num = ~0;
+    memset(buff, 0, sizeof(buff));
+    hr = IStream_Read(stream, buff, sizeof(buff), &num);
+    ok(hr == S_OK, "Failed to read, hr %#x.\n", hr);
+    ok(num == sizeof(buff), "expected %u, got %u\n", sizeof(buff), num);
+    for (i = 0; i < ARRAY_SIZE(buff); i++)
+        ok(buff[i] == 0x11, "expected 0x11, got 0x%02x at %u\n", buff[i], i);
+
+    num = ~0;
+    hr = IStream_Read(stream, buff, sizeof(buff), &num);
+    ok(hr == S_FALSE, "Unexpected hr %#x.\n", hr);
+    ok(num == 0, "expected 0, got 0x%08x\n", num);

hr = IStream_Clone(stream, &stream2);
 todo_wine