kernel32: Set last error to ERROR_ALREADY_EXISTS if CreateFile succeeds and file existed before for CREATE_ALWAYS and OPEN_ALWAYS

[Dmitry Timoshkov]

Hello,

this patch should fix a problem reported in the bug 10452. Actually MSDN
documents that if CreateFile succeeds and a file existed before and creation
disposition is CREATE_ALWAYS or OPEN_ALWAYS GetLastError() should return
ERROR_ALREADY_EXISTS.

Changelog:
    kernel32: Set last error to ERROR_ALREADY_EXISTS if CreateFile succeeds
    and file existed before for CREATE_ALWAYS and OPEN_ALWAYS. Add the tests
    to confirm this behaviour.
---
 dlls/kernel32/file.c       |    9 ++++++-
 dlls/kernel32/tests/file.c |   56 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 1 deletions(-)

diff --git a/dlls/kernel32/file.c b/dlls/kernel32/file.c
index ed97c51..4e05c28 100644
--- a/dlls/kernel32/file.c
+++ b/dlls/kernel32/file.c
@@ -1428,7 +1428,14 @@ HANDLE WINAPI CreateFileW( LPCWSTR filename, DWORD access, DWORD sharing,
         else
             SetLastError( RtlNtStatusToDosError(status) );
     }
-    else SetLastError(0);
+    else
+    {
+        if ((creation == CREATE_ALWAYS && io.Information == FILE_OVERWRITTEN) ||
+            (creation == OPEN_ALWAYS && io.Information == FILE_OPENED))
+            SetLastError( ERROR_ALREADY_EXISTS );
+        else
+            SetLastError( 0 );
+    }
     RtlFreeUnicodeString( &nameW );
 
  done:
diff --git a/dlls/kernel32/tests/file.c b/dlls/kernel32/tests/file.c
index dece7c3..0786964 100644
--- a/dlls/kernel32/tests/file.c
+++ b/dlls/kernel32/tests/file.c
@@ -659,11 +659,39 @@ static void test_CreateFileA(void)
     ret = GetTempFileNameA(temp_path, prefix, 0, filename);
     ok(ret != 0, "GetTempFileNameA error %d\n", GetLastError());
 
+    SetLastError(0xdeadbeef);
     hFile = CreateFileA(filename, GENERIC_READ, 0, NULL,
                         CREATE_NEW, FILE_FLAG_RANDOM_ACCESS, 0);
     ok(hFile == INVALID_HANDLE_VALUE && GetLastError() == ERROR_FILE_EXISTS,
         "CREATE_NEW should fail if file exists and last error value should be ERROR_FILE_EXISTS\n");
 
+    SetLastError(0xdeadbeef);
+    hFile = CreateFileA(filename, GENERIC_READ, FILE_SHARE_READ, NULL,
+                        CREATE_ALWAYS, FILE_FLAG_RANDOM_ACCESS, 0);
+    ok(hFile != INVALID_HANDLE_VALUE && GetLastError() == ERROR_ALREADY_EXISTS,
+       "hFile %p, last error %u\n", hFile, GetLastError());
+
+    CloseHandle(hFile);
+
+    SetLastError(0xdeadbeef);
+    hFile = CreateFileA(filename, GENERIC_READ, FILE_SHARE_READ, NULL,
+                        OPEN_ALWAYS, FILE_FLAG_RANDOM_ACCESS, 0);
+    ok(hFile != INVALID_HANDLE_VALUE && GetLastError() == ERROR_ALREADY_EXISTS,
+       "hFile %p, last error %u\n", hFile, GetLastError());
+
+    CloseHandle(hFile);
+
+    ret = DeleteFileA(filename);
+    ok(ret, "DeleteFileA: error %d\n", GetLastError());
+
+    SetLastError(0xdeadbeef);
+    hFile = CreateFileA(filename, GENERIC_READ, FILE_SHARE_READ, NULL,
+                        OPEN_ALWAYS, FILE_FLAG_RANDOM_ACCESS, 0);
+    ok(hFile != INVALID_HANDLE_VALUE && GetLastError() == 0,
+       "hFile %p, last error %u\n", hFile, GetLastError());
+
+    CloseHandle(hFile);
+
     ret = DeleteFileA(filename);
     ok(ret, "DeleteFileA: error %d\n", GetLastError());
 }
@@ -687,11 +715,39 @@ static void test_CreateFileW(void)
     ret = GetTempFileNameW(temp_path, prefix, 0, filename);
     ok(ret != 0, "GetTempFileNameW error %d\n", GetLastError());
 
+    SetLastError(0xdeadbeef);
     hFile = CreateFileW(filename, GENERIC_READ, 0, NULL,
                         CREATE_NEW, FILE_FLAG_RANDOM_ACCESS, 0);
     ok(hFile == INVALID_HANDLE_VALUE && GetLastError() == ERROR_FILE_EXISTS,
         "CREATE_NEW should fail if file exists and last error value should be ERROR_FILE_EXISTS\n");
 
+    SetLastError(0xdeadbeef);
+    hFile = CreateFileW(filename, GENERIC_READ, FILE_SHARE_READ, NULL,
+                        CREATE_ALWAYS, FILE_FLAG_RANDOM_ACCESS, 0);
+    ok(hFile != INVALID_HANDLE_VALUE && GetLastError() == ERROR_ALREADY_EXISTS,
+       "hFile %p, last error %u\n", hFile, GetLastError());
+
+    CloseHandle(hFile);
+
+    SetLastError(0xdeadbeef);
+    hFile = CreateFileW(filename, GENERIC_READ, FILE_SHARE_READ, NULL,
+                        OPEN_ALWAYS, FILE_FLAG_RANDOM_ACCESS, 0);
+    ok(hFile != INVALID_HANDLE_VALUE && GetLastError() == ERROR_ALREADY_EXISTS,
+       "hFile %p, last error %u\n", hFile, GetLastError());
+
+    CloseHandle(hFile);
+
+    ret = DeleteFileW(filename);
+    ok(ret, "DeleteFileW: error %d\n", GetLastError());
+
+    SetLastError(0xdeadbeef);
+    hFile = CreateFileW(filename, GENERIC_READ, FILE_SHARE_READ, NULL,
+                        OPEN_ALWAYS, FILE_FLAG_RANDOM_ACCESS, 0);
+    ok(hFile != INVALID_HANDLE_VALUE && GetLastError() == 0,
+       "hFile %p, last error %u\n", hFile, GetLastError());
+
+    CloseHandle(hFile);
+
     ret = DeleteFileW(filename);
     ok(ret, "DeleteFileW: error %d\n", GetLastError());
 
-- 
1.5.3.4