2 files changed, 7 insertions, 3 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index ba0af53484d..bf4392d519d 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,9 @@
 2013-11-25  Paul Eggert  <eggert@cs.ucla.edu>
 
+        bool-vector-subsetp is now the normal direction (Bug#15912).
+        * data.c (Fbool_vector_subsetp): Test whether the first argument
+        is a subset of the second one, not the reverse.  Add doc string.
+
         Fix minor problems found by static checking.
         * lread.c (load_path_default): Now static.
         * textprop.c (text_property_stickiness): Be consistent about the
diff --git a/src/data.c b/src/data.c
index ca896897ddf..1fe7a1c9b65 100644
--- a/src/data.c
+++ b/src/data.c
@@ -3242,11 +3242,11 @@ Return the destination vector if it changed or nil otherwise.  */)
 
 DEFUN ("bool-vector-subsetp", Fbool_vector_subsetp,
        Sbool_vector_subsetp, 2, 2, 0,
-       doc: )
+       doc: /* Return t if every t value in A is also t in B, nil otherwise.
+A and B must be bool vectors of the same length.  */)
   (Lisp_Object a, Lisp_Object b)
 {
-  /* Like bool_vector_union, but doesn't modify b.  */
-  return bool_vector_binop_driver (b, a, b, bool_vector_subsetp);
+  return bool_vector_binop_driver (a, b, b, bool_vector_subsetp);
 }
 
 DEFUN ("bool-vector-not", Fbool_vector_not,