server: Improve FSCTL_PIPE_PEEK error handling.

dlls/kernel32/tests/pipe.c

@@ -214,7 +214,6 @@ static void test_CreateNamedPipe(int pipemode)
     test_signaled(hnp);
 
     ret = PeekNamedPipe(hnp, NULL, 0, NULL, &readden, NULL);
-    todo_wine
     ok(!ret && GetLastError() == ERROR_BAD_PIPE, "PeekNamedPipe returned %x (%u)\n",
        ret, GetLastError());
 
@@ -1463,7 +1462,6 @@ static int test_DisconnectNamedPipe(void)
         ok(!ret && GetLastError() == ERROR_PIPE_NOT_CONNECTED, "PeekNamedPipe returned %x (%u)\n",
            ret, GetLastError());
         ret = PeekNamedPipe(hnp, NULL, 0, NULL, &readden, NULL);
-        todo_wine
         ok(!ret && GetLastError() == ERROR_BAD_PIPE, "PeekNamedPipe returned %x (%u)\n",
            ret, GetLastError());
         ok(CloseHandle(hFile), "CloseHandle\n");

dlls/ntdll/tests/pipe.c

@@ -1286,7 +1286,7 @@ static void test_pipe_state(HANDLE pipe, BOOL is_server, DWORD state)
         expected_status = STATUS_PIPE_BROKEN;
         break;
     }
-    todo_wine_if(expected_status && expected_status != STATUS_PIPE_BROKEN)
+    todo_wine_if(expected_status == STATUS_BUFFER_OVERFLOW || expected_status == STATUS_PIPE_DISCONNECTED)
     ok(status == expected_status, "status = %x, expected %x in %s state %u\n",
        status, expected_status, is_server ? "server" : "client", state);
     if (!status)
@@ -1397,7 +1397,7 @@ static void test_pipe_with_data_state(HANDLE pipe, BOOL is_server, DWORD state)
         expected_status = STATUS_BUFFER_OVERFLOW;
         break;
     }
-    todo_wine
+    todo_wine_if(expected_status == STATUS_BUFFER_OVERFLOW || expected_status == STATUS_PIPE_DISCONNECTED)
     ok(status == expected_status, "status = %x, expected %x in %s state %u\n",
        status, expected_status, is_server ? "server" : "client", state);
     if (status == STATUS_BUFFER_OVERFLOW)

server/named_pipe.c

@@ -868,10 +868,17 @@ static int pipe_end_peek( struct pipe_end *pipe_end )
     }
     reply_size -= offsetof( FILE_PIPE_PEEK_BUFFER, Data );
 
-    if (!pipe_end->connection && list_empty( &pipe_end->message_queue ))
+    switch (pipe_end->state)
     {
+    case FILE_PIPE_CONNECTED_STATE:
+        break;
+    case FILE_PIPE_CLOSING_STATE:
+        if (!list_empty( &pipe_end->message_queue )) break;
         set_error( STATUS_PIPE_BROKEN );
         return 0;
+    default:
+        set_error( STATUS_INVALID_PIPE_STATE );
+        return 0;
     }
 
     LIST_FOR_EACH_ENTRY( message, &pipe_end->message_queue, struct pipe_message, entry )