Index: dll/win32/kernel32/file/file.c
===================================================================
--- dll/win32/kernel32/file/file.c	(revision 50815)
+++ dll/win32/kernel32/file/file.c	(working copy)
@@ -24,7 +24,54 @@
 /* FUNCTIONS ****************************************************************/
 
 
+/***********************************************************************
+ *           FILE_name_AtoW
+ *
+ * Convert a file name to Unicode, taking into account the OEM/Ansi API mode.
+ *
+ * If alloc is FALSE uses the TEB static buffer, so it can only be used when
+ * there is no possibility for the function to do that twice, taking into
+ * account any called function.
+ */
+WCHAR *FILE_name_AtoW( LPCSTR name, BOOL alloc )
+{
+    ANSI_STRING str;
+    UNICODE_STRING strW, *pstrW;
+    NTSTATUS status;
 
+    RtlInitAnsiString( &str, name );
+    pstrW = alloc ? &strW : &NtCurrentTeb()->StaticUnicodeString;
+    if (bIsFileApiAnsi)
+        status = RtlOemStringToUnicodeString( pstrW, &str, alloc );
+    else
+        status = RtlAnsiStringToUnicodeString( pstrW, &str, alloc );
+    if (status == STATUS_SUCCESS) return pstrW->Buffer;
+
+    if (status == STATUS_BUFFER_OVERFLOW)
+        SetLastError( ERROR_FILENAME_EXCED_RANGE );
+    else
+        SetLastError( RtlNtStatusToDosError(status) );
+    return NULL;
+}
+
+
+/***********************************************************************
+ *           FILE_name_WtoA
+ *
+ * Convert a file name back to OEM/Ansi. Returns number of bytes copied.
+ */
+DWORD FILE_name_WtoA( LPCWSTR src, INT srclen, LPSTR dest, INT destlen )
+{
+    DWORD ret;
+
+    if (srclen < 0) srclen = strlenW( src ) + 1;
+    if (bIsFileApiAnsi)
+        RtlUnicodeToOemN( dest, destlen, &ret, src, srclen * sizeof(WCHAR) );
+    else
+        RtlUnicodeToMultiByteN( dest, destlen, &ret, (PWSTR)src, srclen * sizeof(WCHAR) );
+    return ret;
+}
+
 PWCHAR
 FilenameA2W(LPCSTR NameA, BOOL alloc)
 {
@@ -1214,23 +1261,18 @@
  */
 UINT WINAPI GetTempFileNameA( LPCSTR path, LPCSTR prefix, UINT unique, LPSTR buffer)
 {
-   WCHAR BufferW[MAX_PATH];
-   PWCHAR PathW;
-   WCHAR PrefixW[3+1];
-   UINT ret;
+    WCHAR *pathW, *prefixW = NULL;
+    WCHAR bufferW[MAX_PATH];
+    UINT ret;
 
-   if (!(PathW = FilenameA2W(path, FALSE)))
-      return 0;
+    if (!(pathW = FILE_name_AtoW( path, FALSE ))) return 0;
+    if (prefix && !(prefixW = FILE_name_AtoW( prefix, TRUE ))) return 0;
 
-   if (prefix)
-      FilenameA2W_N(PrefixW, 3+1, prefix, -1);
+    ret = GetTempFileNameW(pathW, prefixW, unique, bufferW);
+    if (ret) FILE_name_WtoA( bufferW, -1, buffer, MAX_PATH );
 
-   ret = GetTempFileNameW(PathW, prefix ? PrefixW : NULL, unique, BufferW);
-
-   if (ret)
-      FilenameW2A_N(buffer, MAX_PATH, BufferW, -1);
-
-   return ret;
+    HeapFree( GetProcessHeap(), 0, prefixW );
+    return ret;
 }
 
 /***********************************************************************
@@ -1238,10 +1280,11 @@
  */
 UINT WINAPI GetTempFileNameW( LPCWSTR path, LPCWSTR prefix, UINT unique, LPWSTR buffer )
 {
-    static const WCHAR formatW[] = L"%x.tmp";
+    static const WCHAR formatW[] = {'%','x','.','t','m','p',0};
 
     int i;
     LPWSTR p;
+    DWORD attr;
 
     if ( !path || !buffer )
     {
@@ -1249,13 +1292,22 @@
         return 0;
     }
 
-    wcscpy( buffer, path );
-    p = buffer + wcslen(buffer);
+    /* ensure that the provided directory exists */
+    attr = GetFileAttributesW(path);
+    if (attr == INVALID_FILE_ATTRIBUTES || !(attr & FILE_ATTRIBUTE_DIRECTORY))
+    {
+        TRACE("path not found %s\n", debugstr_w(path));
+        SetLastError( ERROR_DIRECTORY );
+        return 0;
+    }
 
+    strcpyW( buffer, path );
+    p = buffer + strlenW(buffer);
+
     /* add a \, if there isn't one  */
     if ((p == buffer) || (p[-1] != '\\')) *p++ = '\\';
 
-    if ( prefix )
+    if (prefix)
         for (i = 3; (i > 0) && (*prefix); i--) *p++ = *prefix++;
 
     unique &= 0xffff;
@@ -1266,7 +1318,10 @@
         /* get a "random" unique number and try to create the file */
         HANDLE handle;
         UINT num = GetTickCount() & 0xffff;
+        static UINT last;
 
+        /* avoid using the same name twice in a short interval */
+        if (last - num < 10) num = last + 1;
         if (!num) num = 1;
         unique = num;
         do
@@ -1278,6 +1333,7 @@
             {  /* We created it */
                 TRACE("created %S\n", buffer);
                 CloseHandle( handle );
+                last = unique;
                 break;
             }
             if (GetLastError() != ERROR_FILE_EXISTS &&
@@ -1287,7 +1343,7 @@
         } while (unique != num);
     }
 
-    TRACE("returning %S\n", buffer);
+    TRACE("returning %s\n", debugstr_w(buffer) );
     return unique;
 }