* alloc.c (mark_object): Use meaningful PVEC_NORMAL_VECTOR.

* lisp.h (enum pvec_type): Adjust comments and omit explicit
initializer for PVEC_NORMAL_VECTOR.

src/ChangeLog

+2012-10-10  Dmitry Antipov  <dmantipov@yandex.ru>
+
+	* alloc.c (mark_object): Use meaningful PVEC_NORMAL_VECTOR.
+	* lisp.h (enum pvec_type): Adjust comments and omit explicit
+	initializer for PVEC_NORMAL_VECTOR.
+
 2012-10-10  Paul Eggert  <eggert@cs.ucla.edu>
 
 	Clean out old termopts cruft.

src/alloc.c

@@ -5689,7 +5689,7 @@ mark_object (Lisp_Object arg)
 	  pvectype = ((ptr->header.size & PVEC_TYPE_MASK)
 		      >> PSEUDOVECTOR_SIZE_BITS);
 	else
-	  pvectype = 0;
+	  pvectype = PVEC_NORMAL_VECTOR;
 
 	if (pvectype != PVEC_SUBR && pvectype != PVEC_BUFFER)
 	  CHECK_LIVE (live_vector_p);

src/lisp.h

@@ -345,15 +345,11 @@ static ptrdiff_t const PSEUDOVECTOR_FLAG
       = PSEUDOVECTOR_FLAG;
 
 /* In a pseudovector, the size field actually contains a word with one
-   PSEUDOVECTOR_FLAG bit set, and exactly one of the following bits to
-   indicate the actual type.
-   We use a bitset, even tho only one of the bits can be set at any
-   particular time just so as to be able to use micro-optimizations such as
-   testing membership of a particular subset of pseudovectors in Fequal.
-   It is not crucial, but there are plenty of bits here, so why not do it?  */
+   PSEUDOVECTOR_FLAG bit set, and one of the following values extracted
+   with PVEC_TYPE_MASK to indicate the actual type.  */
 enum pvec_type
 {
-  PVEC_NORMAL_VECTOR = 0,	/* Unused!  */
+  PVEC_NORMAL_VECTOR,
   PVEC_FREE,
   PVEC_PROCESS,
   PVEC_FRAME,