Subject: [PATCH v23 02/10] pg_stat_file and pg_ls_dir_* to use lstat()..

From: Justin Pryzby <[email-masked]>
Date: Mon, 30 Mar 2020 18:59:16 -0500

pg_ls_dir_* will now skip (no longer show) symbolic links, same as other
non-regular file types, as we advertize we do since 8b6d94cf6.  That seems to
be the intented behavior, since irregular file types are 1) less portable; and,
2) we don't currently show a file's type except for "bool is_dir".

pg_stat_file will now 1) show metadata of links themselves, rather than their
target; and, 2) specifically, show links to directories with "is_dir=false";
and, 3) not error on broken symlinks.
---
 doc/src/sgml/func.sgml          | 2 +-
 src/backend/utils/adt/genfile.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index f068260188..7b1dc264f6 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25908,7 +25908,7 @@ SELECT convert_from(pg_read_binary_file('file_in_utf8.txt'), 'UTF8');
         Returns a record containing the file's size, last access time stamp,
         last modification time stamp, last file status change time stamp (Unix
         platforms only), file creation time stamp (Windows only), and a flag
-        indicating if it is a directory (or a symbolic link to a directory).
+        indicating if it is a directory.
        </para>
        <para>
         This function is restricted to superusers by default, but other users
diff --git a/src/backend/utils/adt/genfile.c b/src/backend/utils/adt/genfile.c
index d34182a7b0..9f4927220b 100644
--- a/src/backend/utils/adt/genfile.c
+++ b/src/backend/utils/adt/genfile.c
@@ -406,7 +406,7 @@ pg_stat_file(PG_FUNCTION_ARGS)
 
 	filename = convert_and_check_filename(filename_t);
 
-	if (stat(filename, &fst) < 0)
+	if (lstat(filename, &fst) < 0)
 	{
 		if (missing_ok && errno == ENOENT)
 			PG_RETURN_NULL();
@@ -632,7 +632,7 @@ pg_ls_dir_files(FunctionCallInfo fcinfo, const char *dir, bool missing_ok)
 
 		/* Get the file info */
 		snprintf(path, sizeof(path), "%s/%s", dir, de->d_name);
-		if (stat(path, &attrib) < 0)
+		if (lstat(path, &attrib) < 0)
 		{
 			/* Ignore concurrently-deleted files, else complain */
 			if (errno == ENOENT)
-- 
2.17.0

--mhjHhnbe5PrRcwjY
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v23-0003-Add-tests-on-pg_ls_dir-before-changing-it.patch"