(jm_FUNC_CHOWN): Add a check to verify that the

uid and gid actually remain unchanged.

diff --git a/m4/chown.m4 b/m4/chown.m4
index 4ae19a9..1fb6203 100644 (file)
--- a/m4/chown.m4
+++ b/m4/chown.m4
@@ -17,6 +17,7 @@ AC_DEFUN(jm_FUNC_CHOWN,
  AC_CACHE_CHECK([for working chown], jm_cv_func_working_chown,
   [AC_TRY_RUN([
 #   include <sys/types.h>
+#   include <stat.h>
 #   include <fcntl.h>
 #   ifdef HAVE_UNISTD_H
 #    include <unistd.h>
@@ -28,7 +29,14 @@ AC_DEFUN(jm_FUNC_CHOWN,
       char *f = "conftestchown";
       if (creat (f, 0600) < 0)
         exit (1);
-      exit (chown (f, (uid_t) -1, (gid_t) -1) == -1 ? 1 : 0);
+      if (stat (f, &before) < 0)
+        exit (1);
+      if (chown (f, (uid_t) -1, (gid_t) -1) == -1)
+        exit (1);
+      if (stat (f, &after) < 0)
+        exit (1);
+      exit ((before.st_uid == after.st_uid
+            && before.st_gid == after.st_gid) ? 0 : 1);
     }
              ],
             jm_cv_func_working_chown=yes,