Martin Buchholz <martin(a)xemacs.org&gt; writes: ^^^^^ ^^^^^^^ no kidding! this didn't help as apparently only sometimes Lisp stuff is called. But I can trigger the crash if I call garbage_collec_1 from the debugger right before the call to tagged_vector_to_alist in glyphs.c:432. The problem is that normalize_image_instantiator potentially calls simple_image_type_normalize, which has the comment (/* This function can call lisp */). the fix is appended below. One could make the gcprotection local to the 'STRINGP' case, but I was to lazy, should I change that? 1998-12-15 Gunnar Evermann <ge204(a)eng.cam.ac.uk&gt; * glyphs.c (normalize_image_instantiator): GCPRO instantiator Index: src/glyphs.c =================================================================== RCS file: /usr/CVSroot/XEmacs/xemacs/src/glyphs.c,v retrieving revision 1.23.2.2 diff -u -r1.23.2.2 glyphs.c --- glyphs.c 1998/12/05 16:55:54 1.23.2.2 +++ glyphs.c 1998/12/15 22:59:26 ＠＠ -466,8 +466,12 ＠＠ Lisp_Object contype, Lisp_Object dest_mask) { + struct gcpro gcpro1; + + GCPRO1(instantiator); + if (IMAGE_INSTANCEP (instantiator)) - return instantiator; + RETURN_UNGCPRO (instantiator); if (STRINGP (instantiator)) instantiator = process_image_string_instantiator (instantiator, contype, ＠＠ -484,9 +488,9 ＠＠ struct image_instantiator_methods * meths = decode_image_instantiator_format (XVECTOR_DATA (instantiator)[0], ERROR_ME); - return IIFORMAT_METH_OR_GIVEN (meths, normalize, + RETURN_UNGCPRO (IIFORMAT_METH_OR_GIVEN (meths, normalize, (instantiator, contype), - instantiator); + instantiator)); } } -- Gunnar Evermann Speech, Vision & Robotics Group Engineering Department Cambridge University