* coding.c (DECODE_COMPOSITION_RULE): If the rule is invalid, goto invalid_code

directly, rather than having caller test rule sign.  This avoids
some unnecessary tests.
* composite.h (COMPOSITION_ENCODE_RULE_VALID): New macro.
(COMPOSITION_ENCODE_RULE): Arguments now must be valid.  This
affects only one use, in DECODE_COMPOSITION_RULE, which is changed.

1 files changed, 7 insertions, 4 deletions

diff --git a/src/composite.h b/src/composite.h
index ffdb57a571e..cfb5db0dc6a 100644
--- a/src/composite.h
+++ b/src/composite.h
@@ -148,12 +148,15 @@ extern Lisp_Object composition_temp;
     COMPOSITION_DECODE_REFS (rule_code, gref, nref);                    \
   } while (0)
 
+/* Nonzero if the global reference point GREF and new reference point NREF are
+   valid.  */
+#define COMPOSITION_ENCODE_RULE_VALID(gref, nref)       \
+  ((unsigned) (gref) < 12 && (unsigned) (nref) < 12)
+
 /* Return encoded composition rule for the pair of global reference
-   point GREF and new reference point NREF.  If arguments are invalid,
-   return -1. */
+   point GREF and new reference point NREF.  Arguments must be valid.  */
 #define COMPOSITION_ENCODE_RULE(gref, nref)             \
-  ((unsigned) (gref) < 12 && (unsigned) (nref) < 12     \
-   ? (gref) * 12 + (nref) : -1)
+  ((gref) * 12 + (nref))
 
 /* Data structure that records information about a composition
    currently used in some buffers or strings.