(set_case_table): Handle nil for EQV with non-nil CANON.

(Fcase_table_p): Accept nil for EQV with non-nil CANON.

1 files changed, 11 insertions, 6 deletions

diff --git a/src/casetab.c b/src/casetab.c
index 5b99d44940f..5a225d4d600 100644
--- a/src/casetab.c
+++ b/src/casetab.c
@@ -47,7 +47,8 @@ See `set-case-table' for more information on these data structures.")
   return (STRING256_P (down)
           && (NILP (up) || STRING256_P (up))
           && ((NILP (canon) && NILP (eqv))
-              || (STRING256_P (canon) && STRING256_P (eqv)))
+              || (STRING256_P (canon)
+                  && (NILP (eqv) || STRING256_P (eqv))))
           ? Qt : Qnil);
 }
 
@@ -99,11 +100,11 @@ UPCASE maps each character to its upper-case equivalent;\n\
  you may use nil and the upcase table will be deduced from DOWNCASE.\n\
 CANONICALIZE maps each character to a canonical equivalent;\n\
  any two characters that are related by case-conversion have the same\n\
- canonical equivalent character.\n\
+ canonical equivalent character; it may be nil, in which case it is\n\
+ deduced from DOWNCASE and UPCASE.\n\
 EQUIVALENCES is a map that cyclicly permutes each equivalence class\n\
- (of characters with the same canonical equivalent).\n\
-Both CANONICALIZE and EQUIVALENCES may be nil, in which case\n\
- both are deduced from DOWNCASE and UPCASE.")
+ (of characters with the same canonical equivalent); it may be nil,\n\
+ in which case it is deduced from CANONICALIZE.")
   (table)
      Lisp_Object table;
 {
@@ -146,13 +147,17 @@ set_case_table (table, standard)
       unsigned char *downvec = XSTRING (down)->data;
 
       canon = Fmake_string (make_number (256), make_number (0));
-      eqv = Fmake_string (make_number (256), make_number (0));
 
       /* Set up the CANON vector; for each character,
          this sequence of upcasing and downcasing ought to
          get the "preferred" lowercase equivalent.  */
       for (i = 0; i < 256; i++)
         XSTRING (canon)->data[i] = downvec[upvec[downvec[i]]];
+    }
+
+  if (NILP (eqv))
+    {
+      eqv = Fmake_string (make_number (256), make_number (0));
 
       compute_trt_inverse (XSTRING (canon)->data, XSTRING (eqv)->data);
     }