zhanghu <kongbaik228@gmail.com> 于2026年3月2日周一 11:17写道：
>
> zhanghu <kongbaik228@gmail.com> 于2026年2月27日周五 16:46写道：
> >
> >
> >
> > Chao Li <li.evan.chao@gmail.com> 于2026年2月27日周五 09:34写道：
> >>
> >>
> >>
> >> > On Feb 26, 2026, at 20:37, Álvaro Herrera <alvherre@kurilemu.de> wrote:
> >> >
> >> > There is at least one more place in the code where this is done.
> >> >
> >>
> >> I did a search with the command: grep -RInE '\*[[:space:]]*[A-Za-z_][A-Za-z0-9_]*\[0\]' src contrib --include='*.c'
> >>
> >> Excluding irrelevant results, there are 3 more occurrences:
> >>
> >> 1 - contrib/basic_archive/basic_archive.c line 105
> >> ```
> >>         if (*newval == NULL || *newval[0] == '\0')
> >>                 return true;
> >> ```
> >>
> >> Here, the code checks *newval first, which implies that the subsequent *newval[0] is unintentional syntax.
> >>
> >> 2 - src/interfaces/ecpg/pgtypeslib/interval.c line 62
> >> ```
> >> int
> >> DecodeInterval(char **field, int *ftype, int nf,        /* int range, */
> >>                            int *dtype, struct /* pg_ */ tm *tm, fsec_t *fsec)
> >> {
> >>   ...
> >>         if (IntervalStyle == INTSTYLE_SQL_STANDARD && *field[0] == '-')
> >>         {
> >>                 /* Check for additional explicit signs */
> >>                 bool            more_signs = false;
> >>
> >>                 for (i = 1; i < nf; i++)
> >>                 {
> >>                         if (*field[i] == '-' || *field[i] == '+')
> >>                         {
> >>                                 more_signs = true;
> >>                                 break;
> >>                         }
> >>                 }
> >> ```
> >>
> >> 3 - src/backend/utils/adt/datatime.c line 3522
> >> ```
> >> int
> >> DecodeInterval(char **field, int *ftype, int nf, int range,
> >>                            int *dtype, struct pg_itm_in *itm_in)
> >> {
> >>  ...
> >>         if (IntervalStyle == INTSTYLE_SQL_STANDARD && nf > 0 && *field[0] == '-')
> >>         {
> >>                 force_negative = true;
> >>                 /* Check for additional explicit signs */
> >>                 for (i = 1; i < nf; i++)
> >>                 {
> >>                         if (*field[i] == '-' || *field[i] == '+')
> >>                         {
> >>                                 force_negative = false;
> >>                                 break;
> >>                         }
> >>                 }
> >>         }
> >> ```
> >>
> >> Where 2&3 makes this patch more interesting.
> >>
> >> Both occurrences are inside functions named DecodeInterval. For non-zero i, the code also performs *field[i]:
> >>
> >> Given this code has been there for years, I don’t believe it is a bug. I checked the callers of DecodeInterval in both files and found that field is defined as:
> >> ```
> >>     char *field[MAXDATEFIELDS];
> >> ```
> >>
> >> This explains why *field[i] works; it is doing the intended thing by getting the first character of the string at array position i.
> >>
> >> However, since the precedence between the [] and * operators frequently confuses people, I suggest adding parentheses to make the intention explicit as *(field[i]). Furthermore, I think we should change the function signatures to use the type char *field[] to reflect the actual type the functions expect. If a caller were to pass a true char ** typed field to DecodeInterval, the current logic would result in a bug.
> >>
> >> See the attached diff for my suggested changes.
> >>
> >> Best regards,
> >> --
> >> Chao Li (Evan)
> >> HighGo Software Co., Ltd.
> >> https://www.highgo.com/
> >>
> >> Hi,
> >>
> >> Thank you all for the reviews and detailed feedback.
> >>
> >> Álvaro, thanks for pointing out that there were additional
> >> occurrences elsewhere in the tree. I have updated the original
> >> patch to address those cases; the revised version is attached
> >> as v2-0001.
> >>
> >> I also appreciate the  review and suggestions from
> >> Chao and Junwang.
> >>
> >> Regarding the additional changes suggested by Chao: they go
> >> somewhat beyond the original scope of my original patch.
> >> To keep the discussion concrete, I have included Chao’s proposed
> >> diff as a separate patch (v2-0002) so it can be reviewed independently.
> >>
> >> I have reviewed v2-0002 locally, and it looks good to me.
> >>
> >> Thanks again for the guidance.
> >>
> >> Regards,
> >> Zhang Hu
> >>
> >>
>
> Hi,
>
> I am planning to add this patch to the current CommitFest, but when
> logging in to commitfest.postgresql.org I get the message:
>
> “You have not passed the cool off period yet.”
>
> It seems my account is still within the cool-off period after registration.
>
> Could someone please add this patch to the CommitFest on my behalf?
>
> Thanks.
>
> Best regards,
> Zhang Hu