Created attachment 515155 [details]
Fix for the bug

Description of problem:
When querying any collection on the mongodb dbshell, the client hangs inside javascript attribute enumeration code.

Version-Release number of selected component (if applicable):
mongodb-1.8.2-4.fc16.x86_64
mongodb-server-1.8.2-4.fc16.x86_64
js-1.8.5-7.fc16.x86_64

How reproducible:
Always

Steps to Reproduce:
$ gdb --args mongo mydb
GNU gdb (GDB) Fedora (7.3.50.20110722-1.fc16)
Copyright (C) 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-redhat-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /usr/bin/mongo...Reading symbols from /usr/lib/debug/usr/bin/mongo.debug...done.
done.
(gdb) r
Starting program: /usr/bin/mongo somedb
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
MongoDB shell version: 1.8.2
[New Thread 0x7ffff53d8700 (LWP 14017)]
connecting to: somedb
[New Thread 0x7ffff45ff700 (LWP 14018)]
> [Thread 0x7ffff45ff700 (LWP 14018) exited]
db.foo.find()
> db.foo.insert({})
> db.foo.find()
####### mongo hangs here, pressed Ctrl+C
Program received signal SIGINT, Interrupt.
0x00000000004ea10d in mongo::bson_enumerate (cx=0x7e00d0, obj=0x7ffff464f558, 
    enum_op=JSENUMERATE_NEXT, statep=0x7fffffffcad0, idp=0x7fffffffcae0)
    at scripting/engine_spidermonkey.cpp:760
760	    JSBool bson_enumerate( JSContext *cx, JSObject *obj, JSIterateOp enum_op, jsval *statep, jsid *idp ) {
Missing separate debuginfos, use: debuginfo-install ncurses-libs-5.9-2.20110716.fc16.x86_64 nspr-4.8.8-4.fc16.x86_64
(gdb) 
(gdb) n
762	        BSONHolder * o = GETHOLDER( cx , obj );
(gdb) 
764	        if ( enum_op == JSENUMERATE_INIT ) {
(gdb) 
777	        BSONFieldIterator * it = (BSONFieldIterator*)JSVAL_TO_PRIVATE( *statep );
(gdb) 
778	        if ( ! it ) {
(gdb) 
791	                *statep = 0;
(gdb) 
793	            return JS_TRUE;
(gdb) 
804	    }
(gdb) 
Snapshot (cx=0x7e00d0, obj=0x7ffff464f558, flags=1, props=0x7fffffffcc50)
    at jsiter.cpp:317
317	                    if (!pobj->enumerate(cx, JSENUMERATE_NEXT, &state, &id))
(gdb) 
319	                    if (state.isNull())
(gdb) 
321	                    if (!Enumerate(cx, obj, pobj, id, true, false, flags, ht, props))
(gdb) 
317	                    if (!pobj->enumerate(cx, JSENUMERATE_NEXT, &state, &id))
(gdb) 
319	                    if (state.isNull())
(gdb) 
321	                    if (!Enumerate(cx, obj, pobj, id, true, false, flags, ht, props))
(gdb) 
317	                    if (!pobj->enumerate(cx, JSENUMERATE_NEXT, &state, &id))
(gdb) 
319	                    if (state.isNull())
(gdb) 
321	                    if (!Enumerate(cx, obj, pobj, id, true, false, flags, ht, props))
(gdb) 
317	                    if (!pobj->enumerate(cx, JSENUMERATE_NEXT, &state, &id))
(gdb) 
319	                    if (state.isNull())
(gdb) 
321	                    if (!Enumerate(cx, obj, pobj, id, true, false, flags, ht, props))
(gdb) 
317	                    if (!pobj->enumerate(cx, JSENUMERATE_NEXT, &state, &id))
(gdb) s
enumerate (idp=0x7fffffffcae0, statep=0x7fffffffcad0, iterop=JSENUMERATE_NEXT, 
    cx=0x7e00d0, this=0x7ffff464f558) at jsobj.h:1257
1257	        js::NewEnumerateOp op = getOps()->enumerate;
(gdb) s
1258	        return (op ? op : js_Enumerate)(cx, this, iterop, statep, idp);
(gdb) s
1257	        js::NewEnumerateOp op = getOps()->enumerate;
(gdb) s
1258	        return (op ? op : js_Enumerate)(cx, this, iterop, statep, idp);
(gdb) s
js_Enumerate (cx=0x7e00d0, obj=0x7ffff464f558, enum_op=JSENUMERATE_NEXT, 
    statep=0x7fffffffcad0, idp=0x7fffffffcae0) at jsobj.cpp:6027
6027	{
(gdb) s
6651	}
(gdb) s
6031	    if (clasp->flags & JSCLASS_NEW_ENUMERATE) {
(gdb) s
6030	    JSEnumerateOp enumerate = clasp->enumerate;
(gdb) s
6031	    if (clasp->flags & JSCLASS_NEW_ENUMERATE) {
(gdb) s
6033	        return ((NewEnumerateOp) enumerate)(cx, obj, enum_op, statep, idp);
(gdb) s
6043	}
(gdb) s
6033	        return ((NewEnumerateOp) enumerate)(cx, obj, enum_op, statep, idp);
(gdb) s
mongo::bson_enumerate (cx=0x7e00d0, obj=0x7ffff464f558, 
    enum_op=JSENUMERATE_NEXT, statep=0x7fffffffcad0, idp=0x7fffffffcae0)
    at scripting/engine_spidermonkey.cpp:760
760	    JSBool bson_enumerate( JSContext *cx, JSObject *obj, JSIterateOp enum_op, jsval *statep, jsid *idp ) {
(gdb) n
762	        BSONHolder * o = GETHOLDER( cx , obj );
(gdb) n
764	        if ( enum_op == JSENUMERATE_INIT ) {
(gdb) n
777	        BSONFieldIterator * it = (BSONFieldIterator*)JSVAL_TO_PRIVATE( *statep );
(gdb) n
778	        if ( ! it ) {
(gdb) n
791	                *statep = 0;
(gdb) n
793	            return JS_TRUE;
(gdb) p statep
$1 = (jsval *) 0x7fffffffcad0
(gdb) p *statep
$2 = 0
(gdb) 
---------------------

I didn't report this upstream yet because I still have to find a way to build mongodb from git without errors (maybe I'm just missing some config option to use the right flags).