[BUG] Infinite loop on YAML.dump (Re: ruby-list:40801)

Hello.

Kouhei Yanagita reported infinite loop bug on YAML.dump.
Please try attached file.

This bug occurs because 7th anchor tag never be generated. (if block never be executed)

Index: emitter.c
===================================================================
RCS file: /src/ruby/ext/syck/emitter.c,v
retrieving revision 1.11
diff -u -w -b -p -r1.11 emitter.c
--- emitter.c	6 May 2004 06:29:56 -0000	1.11
+++ emitter.c	8 May 2005 06:19:25 -0000
@@ -383,6 +383,8 @@ syck_emitter_start_obj( SyckEmitter *e, 
                  */
                 idx = e->anchors->num_entries + 1;
 
+                printf("------> %d %d %d\n", idx, n->pos, e->bufpos);
+
                 /*
                  * Create the anchor tag
                  */
                if ( n->pos >= e->bufpos )
                {


------> 1 3 0
------> 2 680 0
------> 3 1357 0
------> 4 2034 0
------> 5 2511 0
------> 6 3188 0
------> 7 3865 4094
（...）
------> 7 3865 8148
（...）

e->bufpos keeps incresing in syck_emitter_flush (by e->bufpos += check_room)

/////////////////////////////////////////////

I'm wondering if this code can be executed correctly when coresponding part of buffer is flushed.

                    /*
                     * Write the anchor into the buffer
                     */
                    S_MEMMOVE( start + alen, start, char, e->marker - start );
                    S_MEMCPY( start + 1, anchor_name, char, strlen( anchor_name ) );
                    start[0] = '&';
                    start[alen - 1] = ' ';
                    e->marker += alen;


Nobody can predict which object needs anchor, so should "fixed size buffer & flush" be abondoned
and whole YAML document be held in memory?

Thank you.