Re: [PATCH] Fix error message in RemoveWalSummaryIfOlderThan to indicate file removal failure

> Likely so. This one should be backpatched, as the error generated
> could be confusing if faced. That's very unlikely so, still.. I'll
> look at other places in the tree for similar inconsistencies, while on
> it.

Hi Michael,

Thank you for helping to address this! I’ve gone back and reviewed the code, and noticed `OpenWalSummaryFile`:
```
File
OpenWalSummaryFile(WalSummaryFile *ws, bool missing_ok)
{
char path[MAXPGPATH];
File file;

snprintf(path, MAXPGPATH,
XLOGDIR "/summaries/%08X%08X%08X%08X%08X.summary",
ws->tli,
LSN_FORMAT_ARGS(ws->start_lsn),
LSN_FORMAT_ARGS(ws->end_lsn));

file = PathNameOpenFile(path, O_RDONLY);
if (file < 0 && (errno != EEXIST || !missing_ok))
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open file \"%s\": %m", path)));

return file;
}
```
I’m thinking of changing `errno != EEXIST` to `errno != ENOENT` here — would you think this adjustment is appropriate?

--
Regards,
Man Zeng