Re: BUG #18657: Using JSON_OBJECTAGG with volatile function leads to segfault

On Wed, Oct 16, 2024 at 6:19 PM Tender Wang <tndrwang@gmail.com> wrote:
> Amit Langote <amitlangote09@gmail.com> 于2024年10月16日周三 17:14写道：
>> On Wed, Oct 16, 2024 at 6:11 PM Tender Wang <tndrwang@gmail.com> wrote:
>> > Amit Langote <amitlangote09@gmail.com> 于2024年10月16日周三 17:06写道：
>> >>
>> >> On Wed, Oct 16, 2024 at 5:20 PM Tender Wang <tndrwang@gmail.com> wrote:
>> >> > Amit Langote <amitlangote09@gmail.com> 于2024年10月16日周三 08:35写道：
>> >> >>
>> >> >> On Wed, Oct 16, 2024 at 9:19 AM Michael Paquier <michael@paquier.xyz> wrote:
>> >> >> > On Tue, Oct 15, 2024 at 11:00:01AM +0000, PG Bug reporting form wrote:
>> >> >> > > First bad commit for this anomaly is b6e1157e7.
>> >> >> >
>> >> >> > Amit, any thoughts?
>> >> >>
>> >> >> Will look into it, thanks.
>> >> > Hi,
>> >> >
>> >> > I debug this issue, and I find that:
>> >> > after  b6e1157e7,  we shouldn't walk JsonValueExpr.raw_expr in expression_tree_walker_impl(), which
>> >> > is called in preprocess_aggrefs().
>> >> >
>> >> > I try to above solution, no crashed again.
>> >>
>> >> Thanks for the analysis.  That is my conclusion as well.
>> >>
>> >> Attached a patch.
>> >>
>> >
>> > Yeah, yours look more better than mine.  And the typo in my attached patch, is that right?
>> > JSON_OBJECT() should be JSON_OBJECTAGG()  near  transformJsonObjectAgg()
>>
>> Yeah, the typo needs to be fixed as well.  Thanks for the patch.
>>
>> So, attaching 0002 for that.

I've pushed 0002 in advance.

I realized I hadn't explained in the commit message why the outputs of
some existing tests changed, so I decided to give it more thought
before pushing 0001. The changes seem harmless at first glance, but I
want to consider them further.

Also, it might be better to leave a comment where the commit is
removing code, as follows:

-                if (WALK(jve->raw_expr))
-                    return true;
+                /* Ignore raw_expr because it's not relevant at runtime. */

--
Thanks, Amit Langote