1 files changed, 18 insertions, 11 deletions

diff --git a/src/chartab.c b/src/chartab.c
index efe23eca83f..1d4ac04312a 100644
--- a/src/chartab.c
+++ b/src/chartab.c
@@ -589,8 +589,6 @@ DEFUN ("set-char-table-extra-slot", Fset_char_table_extra_slot,
   (Lisp_Object char_table, Lisp_Object n, Lisp_Object value)
 {
   CHECK_CHAR_TABLE (char_table);
-  if (EQ (XCHAR_TABLE (char_table)->purpose, Qchar_code_property_table))
-    error ("Can't change extra-slot of char-code-property-table");
   CHECK_NUMBER (n);
   if (XINT (n) < 0
       || XINT (n) >= CHAR_TABLE_EXTRA_SLOTS (XCHAR_TABLE (char_table)))
@@ -1095,22 +1093,31 @@ map_char_table_for_charset (void (*c_function) (Lisp_Object, Lisp_Object),
 
 /* Unicode character property tables.
 
-   This section provides a convenient and efficient way to get a
-   Unicode character property from C code (from Lisp, you must use
-   get-char-code-property).
+   This section provides a convenient and efficient way to get Unicode
+   character properties of characters from C code (from Lisp, you must
+   use get-char-code-property).
 
-   The typical usage is to get a char-table for a specific property at
-   a proper initialization time as this:
+   The typical usage is to get a char-table object for a specific
+   property like this (use of the "bidi-class" property below is just
+   an example):
 
         Lisp_Object bidi_class_table = uniprop_table (intern ("bidi-class"));
 
-   and get a property value for character CH as this:
+   (uniprop_table can return nil if it fails to find data for the
+   named property, or if it fails to load the appropriate Lisp support
+   file, so the return value should be tested to be non-nil, before it
+   is used.)
 
-        Lisp_Object bidi_class = CHAR_TABLE_REF (CH, bidi_class_table);
+   To get a property value for character CH use CHAR_TABLE_REF:
+
+        Lisp_Object bidi_class = CHAR_TABLE_REF (bidi_class_table, CH);
 
    In this case, what you actually get is an index number to the
    vector of property values (symbols nil, L, R, etc).
 
+   The full list of Unicode character properties supported by Emacs is
+   documented in the ELisp manual, in the node "Character Properties".
+
    A table for Unicode character property has these characteristics:
 
    o The purpose is `char-code-property-table', which implies that the
@@ -1122,7 +1129,7 @@ map_char_table_for_charset (void (*c_function) (Lisp_Object, Lisp_Object),
    means that we don't have to decode values.
 
    o The third extra slot is a Lisp function, an index (integer) to
-   the array uniprop_enncoder[], or nil.  If it is a Lisp function, we
+   the array uniprop_encoder[], or nil.  If it is a Lisp function, we
    can't use such a table from C (at the moment).  If it is nil, it
    means that we don't have to encode values.  */
 
@@ -1310,7 +1317,7 @@ uniprop_get_encoder (Lisp_Object table)
    function may load a Lisp file and thus may cause
    garbage-collection.  */
 
-static Lisp_Object
+Lisp_Object
 uniprop_table (Lisp_Object prop)
 {
   Lisp_Object val, table, result;