Examples of errors detected by the V587 diagnostic

V587. Suspicious sequence of assignments: A = B; B = A;.

Windows 8 Driver Samples

V587 An odd sequence of assignments of this kind: A = B; B = A;. Check lines: 2572, 2573. fileinfo.c 2573

NTSTATUS
FatSetDispositionInfo (....)
{
  ....
  TmpChar = LocalBuffer[0];
  LocalBuffer[0] = TmpChar;
  ....
}

Mozilla Firefox

V587 An odd sequence of assignments of this kind: A = B; B = A;. Check lines: 358, 360. nsregion.cpp 360

void nsRegion::SimplifyOutwardByArea(uint32_t aThreshold)
{
  ....
  topRects = destRect;
  bottomRects = bottomRectsEnd;
  destRect = topRects;
  ....
}

LibreOffice

V587 An odd sequence of assignments of this kind: A = B; B = A;. Check lines: 565, 566. tabbar.cxx 566

void TabBar::ImplGetColors(....)
{
  ....
  aTempColor = rFaceTextColor;
  rFaceTextColor = rSelectTextColor;
  rSelectTextColor = rFaceTextColor;
  ....
}

Bad swap.

Git

V587 An odd sequence of assignments of this kind: A = B; B = A;. Check lines: 2463, 2465. dir.c 2465

static int read_one_dir(struct read_data *rd, ....)
{
  const unsigned char *next, *data = rd->data;
  ....
  data = next;
  next = data;
  ....
}

GNU GRUB

V587 An odd sequence of assignments of this kind: A = B; B = A;. Check lines: 338, 339. relocator.c 339

static void free_subchunk (....)
{
  switch (subchu->type)
    {
    case CHUNK_TYPE_REGION_START:
      {
       grub_mm_region_t r1, r2, *rp;
       ....
       if (*rp)
       {
        ....
       }
       else
       {
         r1->pre_size = pre_size;
         r1->size = (r2 - r1) * sizeof (*r2);
         for (rp = &grub_mm_base; *rp; rp = &((*rp)->next))
           if ((*rp)->size > r1->size)
             break;
         r1->next = *rp;               // <=
         *rp = r1->next;               // <=
         h = (grub_mm_header_t) (r1 + 1);
         r1->first = h;
         h->next = h;
         h->magic = GRUB_MM_FREE_MAGIC;
         h->size = (r2 - r1 - 1);
       }
       ....
    }
  ....
}

EFL Core Libraries

V587 An odd sequence of assignments of this kind: A = B; B = A;. Check lines: 1006, 1007. ecore_x_events.c 1007

void
_ecore_x_event_handle_focus_in(XEvent *xevent)
{
  ....
   e->time = _ecore_x_event_last_time;
   _ecore_x_event_last_time = e->time;
  ....
}

Similar errors can be found in some other places:

• V587 An odd sequence of assignments of this kind: A = B; B = A;. Check lines: 1050, 1051. ecore_x_events.c 1051

ORCT2

V587 An odd sequence of assignments of this kind: A = B; B = A;. Check lines: 1115, 1118. libopenrct2ui MouseInput.cpp 1118

void process_mouse_over(....)
{
  ....
  switch (window->widgets[widgetId].type)
  {
    case WWT_VIEWPORT:
      ebx = 0;
      edi = cursorId;                                 // <=
      // Window event WE_UNKNOWN_0E was called here,
      // but no windows actually implemented a handler and
      // it's not known what it was for
      cursorId = edi;                                 // <=
      if ((ebx & 0xFF) != 0)
      {
        set_cursor(cursorId);
        return;
      }
      break;
      ....
  }
  ....
}

CodeLite

V587 An odd sequence of assignments of this kind: A = B; B = A;. Check lines: 483, 484. SqlCommandPanel.cpp:484, SqlCommandPanel.cpp:483

wxArrayString SQLCommandPanel::ParseSql() const
{
  ....
  int startPos = 0;
  int stopPos = 0;
  ....
  startPos = stopPos;
  stopPos = startPos;
  ....
}