From fc4e5af30749eadc2acf98de426fa51910f8766b Mon Sep 17 00:00:00 2001 From: Thomas Munro Date: Thu, 28 Jul 2022 14:13:37 +1200 Subject: [PATCH] Fix get_dirent_type() for symlinks on MinGW/MSYS. On Windows with MSVC, get_dirent_type() was recently made to return DT_LNK for junction points by commit 9d3444dc, which fixed some defective dirent.c code. On Windows with Cygwin, get_dirent_type() already worked for symlinks, as it does on POSIX systems, because Cygwin has its own fake symlinks that behave like POSIX (on closer inspection, Cygwin's dirent has the BSD d_type extension but it's probably always DT_UNKNOWN, so we fall back to lstat(), which understands Cygwin symlinks with S_ISLNK()). On Windows with MinGW/MSYS, we need extra code, because the MinGW runtime has its own readdir() without d_type, and the lstat()-based fallback has no knowledge of our convention for treating junctions as symlinks. Back-patch to 14, where get_dirent_type() landed. Reported-by: Andrew Dunstan Discussion: https://postgr.es/m/b9ddf605-6b36-f90d-7c30-7b3e95c46276%40dunslane.net --- src/common/file_utils.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/src/common/file_utils.c b/src/common/file_utils.c index 19d308ad1f9..966b987d648 100644 --- a/src/common/file_utils.c +++ b/src/common/file_utils.c @@ -465,5 +465,21 @@ get_dirent_type(const char *path, #endif } +#if defined(WIN32) && !defined(_MSC_VER) + + /* + * If we're on native Windows (not Cygwin, which has its own POSIX + * symlinks), but not using the MSVC compiler, then we're using a + * readdir() emulation provided by the MinGW runtime that has no d_type. + * Since the lstat() fallback code reports junction points as directories, + * we need an extra system call to check if we should report them as + * symlinks instead, following our convention. + */ + if (result == PGFILETYPE_DIR && + !look_through_symlinks && + pgwin32_is_junction(path)) + result = PGFILETYPE_LNK; +#endif + return result; }