zhanghu <[email protected]> 于2026年2月27日周五 16:46写道： > > > > Chao Li <[email protected]> 于2026年2月27日周五 09:34写道： >> >> >> >> > On Feb 26, 2026, at 20:37, Álvaro Herrera <[email protected]> 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
