pango_glyph_string_extents_range (PangoGlyphString *glyphs,
				  int               start,
				  int               end,
				  PangoFont        *font,
				  PangoRectangle   *ink_rect,
				  PangoRectangle   *logical_rect)
{
  int x_pos = 0;
  int i;

  /* Note that the handling of empty rectangles for ink
   * and logical rectangles is different. A zero-height ink
   * rectangle makes no contribution to the overall ink rect,
   * while a zero-height logical rect still reserves horizontal
   * width. Also, we may return zero-width, positive height
   * logical rectangles, while we'll never do that for the
   * ink rect.
   */
  g_return_if_fail (start <= end);

  if (G_UNLIKELY (!ink_rect && !logical_rect))
    return;

  if (ink_rect)
    {
      ink_rect->x = 0;
      ink_rect->y = 0;
      ink_rect->width = 0;
      ink_rect->height = 0;
    }

  if (logical_rect)
    {
      logical_rect->x = 0;
      logical_rect->y = 0;
      logical_rect->width = 0;
      logical_rect->height = 0;
    }

  for (i = start; i < end; i++)
    {
      PangoRectangle glyph_ink;
      PangoRectangle glyph_logical;

      PangoGlyphGeometry *geometry = &glyphs->glyphs[i].geometry;

      pango_font_get_glyph_extents (font, glyphs->glyphs[i].glyph,
				    ink_rect ? &glyph_ink : NULL,
				    logical_rect ? &glyph_logical : NULL);

      if (ink_rect && glyph_ink.width != 0 && glyph_ink.height != 0)
	{
	  if (ink_rect->width == 0 || ink_rect->height == 0)
	    {
	      ink_rect->x = x_pos + glyph_ink.x + geometry->x_offset;
	      ink_rect->width = glyph_ink.width;
	      ink_rect->y = glyph_ink.y + geometry->y_offset;
	      ink_rect->height = glyph_ink.height;
	    }
	  else
	    {
	      int new_x, new_y;

	      new_x = MIN (ink_rect->x, x_pos + glyph_ink.x + geometry->x_offset);
	      ink_rect->width = MAX (ink_rect->x + ink_rect->width,
				     x_pos + glyph_ink.x + glyph_ink.width + geometry->x_offset) - new_x;
	      ink_rect->x = new_x;

	      new_y = MIN (ink_rect->y, glyph_ink.y + geometry->y_offset);
	      ink_rect->height = MAX (ink_rect->y + ink_rect->height,
				      glyph_ink.y + glyph_ink.height + geometry->y_offset) - new_y;
	      ink_rect->y = new_y;
	    }
	}

      if (logical_rect)
	{
	  logical_rect->width += geometry->width;

	  if (i == start)
	    {
	      logical_rect->y = glyph_logical.y;
	      logical_rect->height = glyph_logical.height;
	    }
	  else
	    {
	      int new_y = MIN (logical_rect->y, glyph_logical.y);
	      logical_rect->height = MAX (logical_rect->y + logical_rect->height,
					  glyph_logical.y + glyph_logical.height) - new_y;
	      logical_rect->y = new_y;
	    }
	}

      x_pos += geometry->width;
    }
}

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.