[pypy-commit] pypy default: Add comment

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r68823:68a4e65eba06
Date: 2014-01-21 16:49 +0100
http://bitbucket.org/pypy/pypy/changeset/68a4e65eba06/

Log:	Add comment

diff --git a/rpython/jit/metainterp/pyjitpl.py b/rpython/jit/metainterp/pyjitpl.py
--- a/rpython/jit/metainterp/pyjitpl.py
+++ b/rpython/jit/metainterp/pyjitpl.py
@@ -623,6 +623,10 @@
         tobox = self.metainterp.heapcache.getfield(box, fielddescr)
         if tobox is valuebox:
             return
+        # The following test is disabled because buggy.  It is supposed
+        # to be: not(we're writing null into a freshly allocated object)
+        # but the bug is that is_unescaped() can be True even after the
+        # field cache is cleared --- see test_ajit:test_unescaped_write_zero
         if 1:  # tobox is not None or not self.metainterp.heapcache.is_unescaped(box) or not isinstance(valuebox, Const) or valuebox.nonnull():
             self.execute_with_descr(rop.SETFIELD_GC, fielddescr, box, valuebox)
         self.metainterp.heapcache.setfield(box, valuebox, fielddescr)