Re: Display performance degradation

[YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>]

While I was looking at font caching code, I found a part that seems to
be wrong, though it is not directly related to the original
performance issue.

Fclear_font_cache (in src/font.c):

  4484		    val = XCDR (cache);
  4485		    while (! NILP (val)
  4486			   && ! EQ (XCAR (XCAR (val)), driver_list->driver->type))
  4487		      val = XCDR (val);
  4488		    font_assert (! NILP (val));
  4489		    val = XCDR (XCAR (val));
  4490		    if (XINT (XCAR (val)) == 0)
  4491		      {
  4492			font_clear_cache (f, XCAR (val), driver_list->driver);
  4493			XSETCDR (cache, XCDR (val));
  4494		      }
  4495		  }

At line 4490, XCAR (val) is expected to be of type Lisp integer.  But
it is also passed to font_clear_cache at line 4492, which seems to
expect the value of `val' as of line 4488 rather than the one assigned
at line 4489.

				     YAMAMOTO Mitsuharu
				mituharu@math.s.chiba-u.ac.jp