fchmod-tests, fchmodat tests, lchmod tests: Add more tests

[Bruno Haible]

It smells like additional tests for fchmod(), fchmodat(), lchmod() could
uncover bugs on some platforms. So I'm adding more tests.


2021-01-09  Bruno Haible  <br...@clisp.org>

        fchmod-tests, fchmodat tests, lchmod tests: Add more tests.
        * tests/test-fchmod.c: Include <fcntl.h>.
        (BASE): New macro.
        (main): Add more tests.
        * tests/test-fchmodat.c (main): Add more tests.
        * tests/test-lchmod.c (main): Likewise.

diff --git a/tests/test-fchmod.c b/tests/test-fchmod.c
index 43b70ac..f8db9e5 100644
--- a/tests/test-fchmod.c
+++ b/tests/test-fchmod.c
@@ -22,10 +22,13 @@
 SIGNATURE_CHECK (fchmod, int, (int, mode_t));
 
 #include <errno.h>
+#include <fcntl.h>
 #include <unistd.h>
 
 #include "macros.h"
 
+#define BASE "test-fchmod."
+
 int
 main (void)
 {
@@ -42,5 +45,24 @@ main (void)
     ASSERT (errno == EBADF);
   }
 
+  /* Test that fchmod works on regular files.  */
+  {
+    struct stat statbuf;
+    int fd;
+
+    unlink (BASE "file");
+    ASSERT (close (creat (BASE "file", 0600)) == 0);
+    fd = open (BASE "file", O_RDWR);
+    ASSERT (fd >= 0);
+    ASSERT (fchmod (fd, 0400) == 0);
+    ASSERT (stat (BASE "file", &statbuf) >= 0);
+    ASSERT ((statbuf.st_mode & 0700) == 0400);
+    ASSERT (close (fd) == 0);
+
+    /* Clean up.  */
+    ASSERT (chmod (BASE "file", 0600) == 0);
+    ASSERT (unlink (BASE "file") == 0);
+  }
+
   return 0;
 }
diff --git a/tests/test-fchmodat.c b/tests/test-fchmodat.c
index 5e4d2b0..6d430fa 100644
--- a/tests/test-fchmodat.c
+++ b/tests/test-fchmodat.c
@@ -46,6 +46,39 @@ main (void)
     ASSERT (errno == EBADF);
   }
 
+  /* Test that fchmodat works on regular files.  */
+  {
+    struct stat statbuf;
+
+    unlink (BASE "file");
+    ASSERT (close (creat (BASE "file", 0600)) == 0);
+    ASSERT (fchmodat (AT_FDCWD, BASE "file", 0400, 0) == 0);
+    ASSERT (stat (BASE "file", &statbuf) >= 0);
+    ASSERT ((statbuf.st_mode & 0700) == 0400);
+
+    errno = 0;
+    ASSERT (fchmodat (AT_FDCWD, BASE "file/", 0600, 0) == -1);
+    ASSERT (errno == ENOTDIR);
+
+    /* Clean up.  */
+    ASSERT (chmod (BASE "file", 0600) == 0);
+    ASSERT (unlink (BASE "file") == 0);
+  }
+
+  /* Test that fchmodat works on directories.  */
+  {
+    struct stat statbuf;
+    rmdir (BASE "dir");
+    ASSERT (mkdir (BASE "dir", 0700) == 0);
+    ASSERT (fchmodat (AT_FDCWD, BASE "dir", 0500, 0) == 0);
+    ASSERT (stat (BASE "dir", &statbuf) >= 0);
+    ASSERT ((statbuf.st_mode & 0700) == 0500);
+    ASSERT (fchmodat (AT_FDCWD, BASE "dir/", 0700, 0) == 0);
+
+    /* Clean up.  */
+    ASSERT (rmdir (BASE "dir") == 0);
+  }
+
   /* Test that fchmodat works on non-symlinks, when given
      the AT_SYMLINK_NOFOLLOW flag.  */
   {
diff --git a/tests/test-lchmod.c b/tests/test-lchmod.c
index 7b8e8a1..d4c811e 100644
--- a/tests/test-lchmod.c
+++ b/tests/test-lchmod.c
@@ -33,7 +33,7 @@ SIGNATURE_CHECK (lchmod, int, (const char *, mode_t));
 int
 main (void)
 {
-  /* Test that lchmod works on non-symlinks.  */
+  /* Test that lchmod works on regular files.  */
   {
     struct stat statbuf;
     unlink (BASE "file");
@@ -41,11 +41,31 @@ main (void)
     ASSERT (lchmod (BASE "file", 0400) == 0);
     ASSERT (stat (BASE "file", &statbuf) >= 0);
     ASSERT ((statbuf.st_mode & 0700) == 0400);
+
+    errno = 0;
+    ASSERT (lchmod (BASE "file/", 0600) == -1);
+    ASSERT (errno == ENOTDIR);
+
     /* Clean up.  */
     ASSERT (chmod (BASE "file", 0600) == 0);
     ASSERT (unlink (BASE "file") == 0);
   }
 
+  /* Test that lchmod works on directories.  */
+  {
+    struct stat statbuf;
+
+    rmdir (BASE "dir");
+    ASSERT (mkdir (BASE "dir", 0700) == 0);
+    ASSERT (lchmod (BASE "dir", 0500) == 0);
+    ASSERT (stat (BASE "dir", &statbuf) >= 0);
+    ASSERT ((statbuf.st_mode & 0700) == 0500);
+    ASSERT (lchmod (BASE "dir/", 0700) == 0);
+
+    /* Clean up.  */
+    ASSERT (rmdir (BASE "dir") == 0);
+  }
+
   /* Test that lchmod on symlinks does not modify the symlink target.  */
   {
     unlink (BASE "file");