Re: [PATCH] Fix wrong comment in JsonTablePlanJoinNextRow()

On Thu, Apr 16, 2026 at 12:03 PM Amit Langote <amitlangote09@gmail.com> wrote:
> On Thu, Apr 16, 2026 at 11:05 AM Chao Li <li.evan.chao@gmail.com> wrote:
> > > On Apr 15, 2026, at 16:28, 胡传文 <463945512@qq.com> wrote:
> > >
> > > Hi,
> > > Found a misleading comment in JsonTablePlanJoinNextRow() while reading
> > > the JSON_TABLE execution code.
> > > The function returns false when both siblings are exhausted (meaning no
> > > more rows), but the comment says "there are more rows" — the exact
> > > opposite of what's happening. The code itself is correct.
> > > if (!JsonTablePlanNextRow(planstate->right))
> > > {
> > > /* Right sibling ran out of row, so there are more rows. */ /* wrong */
> > > return false;
> > > }
> > > A reader might reasonably treat this as a bug and flip the return value,
> > > which would cause JSON_TABLE UNION plans to loop indefinitely.
> > > Patch attached.
>
> Thanks for the report and the patch.
>
> > The fix looks correct to me. I guess “no” was just unintentionally missed.
> >
> > A small comment, I just feel “too” you newly added might not be needed.
>
> Actually, I'd keep it, because it ties the comment to the left-sibling
> check just above.
>
> Will push the attached down to v17.

Done.

-- 
Thanks, Amit Langote