From 58651d8dd6a56af306a361e2c386db798164c0f1 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Tue, 30 Nov 2021 09:55:50 +0900 Subject: [PATCH] Fix compatibility thinko for fstat() on standard streams in win32stat.c MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit GetFinalPathNameByHandleA() cannot be used in compilation environments where _WIN32_WINNT < 0x0600, meaning at least Windows XP used by some buildfarm members under MinGW that Postgres still needs to support. This was reported as a compilation warning by the buildfarm, but this is actually worse than the report as the code would have not worked. Instead, this switches to GetFileInformationByHandle() that is able to fail for standard streams and succeed for redirected ones, which is what we are looking for herein the code emulating fstat(). We also know that it is able to work in all the environments still supported, thanks to the existing logic of win32stat.c. Issue introduced by 10260c7, so backpatch down to 14. Reported-by: Justin Pryzby, via buildfarm member jacana Author: Michael Paquier Reviewed-by: Juan José Santamaría Flecha Discussion: https://postgr.es/m/20211129050122.GK17618@telsasoft.com Backpatch-through: 14 --- src/port/win32stat.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/port/win32stat.c b/src/port/win32stat.c index 3956fac060..426e01f0ef 100644 --- a/src/port/win32stat.c +++ b/src/port/win32stat.c @@ -289,7 +289,7 @@ int _pgfstat64(int fileno, struct stat *buf) { HANDLE hFile = (HANDLE) _get_osfhandle(fileno); - char path[MAX_PATH]; + BY_HANDLE_FILE_INFORMATION fiData; if (hFile == INVALID_HANDLE_VALUE || buf == NULL) { @@ -306,7 +306,7 @@ _pgfstat64(int fileno, struct stat *buf) if ((fileno == _fileno(stdin) || fileno == _fileno(stdout) || fileno == _fileno(stderr)) && - GetFinalPathNameByHandleA(hFile, path, MAX_PATH, VOLUME_NAME_NT) == 0) + !GetFileInformationByHandle(hFile, &fiData)) { memset(buf, 0, sizeof(*buf)); buf->st_mode = _S_IFCHR;