Remove unused function rec_offs_nth_null().

rec_offs_nth_extern(): Return zero/nonzero instead of FALSE/TRUE.


innobase/row/row0upd.c:
  Normalize the return value of rec_offs_nth_extern() to FALSE/TRUE.
  Avoid a repeated call to upd_ext_vec_contains().

innobase/include/rem0rec.h

@@ -303,21 +303,12 @@ rec_offs_comp(
 				/* out: TRUE if compact format */
 	const ulint*	offsets);/* in: array returned by rec_get_offsets() */
 /**********************************************************
-Returns TRUE if the nth field of rec is SQL NULL. */
+Returns nonzero if the extern bit is set in nth field of rec. */
 UNIV_INLINE
-ibool
-rec_offs_nth_null(
-/*==============*/
-				/* out: TRUE if SQL NULL */
-	const ulint*	offsets,/* in: array returned by rec_get_offsets() */
-	ulint		n);	/* in: nth field */
-/**********************************************************
-Returns TRUE if the extern bit is set in nth field of rec. */
-UNIV_INLINE
-ibool
+ulint
 rec_offs_nth_extern(
 /*================*/
-				/* out: TRUE if externally stored */
+				/* out: nonzero if externally stored */
 	const ulint*	offsets,/* in: array returned by rec_get_offsets() */
 	ulint		n);	/* in: nth field */
 /**********************************************************

innobase/include/rem0rec.ic

@@ -939,32 +939,19 @@ rec_offs_comp(
 }
 
 /**********************************************************
-Returns TRUE if the nth field of rec is SQL NULL. */
+Returns nonzero if the extern bit is set in nth field of rec. */
 UNIV_INLINE
-ibool
-rec_offs_nth_null(
-/*==============*/
-				/* out: TRUE if SQL NULL */
-	const ulint*	offsets,/* in: array returned by rec_get_offsets() */
-	ulint		n)	/* in: nth field */
-{
-	ut_ad(rec_offs_validate(NULL, NULL, offsets));
-	ut_ad(n < rec_offs_n_fields(offsets));
-	return((rec_offs_base(offsets)[1 + n] & REC_OFFS_SQL_NULL) != 0);
-}
-/**********************************************************
-Returns TRUE if the extern bit is set in nth field of rec. */
-UNIV_INLINE
-ibool
+ulint
 rec_offs_nth_extern(
 /*================*/
-				/* out: TRUE if externally stored */
+				/* out: nonzero if externally stored */
 	const ulint*	offsets,/* in: array returned by rec_get_offsets() */
 	ulint		n)	/* in: nth field */
 {
 	ut_ad(rec_offs_validate(NULL, NULL, offsets));
 	ut_ad(n < rec_offs_n_fields(offsets));
-	return((rec_offs_base(offsets)[1 + n] & REC_OFFS_EXTERNAL) != 0);
+	return(UNIV_UNLIKELY(rec_offs_base(offsets)[1 + n]
+				& REC_OFFS_EXTERNAL));
 }
 
 /**********************************************************

innobase/row/row0upd.c

@@ -815,9 +815,10 @@ row_upd_build_difference_binary(
 			goto skip_compare;
 		}
 
-		extern_bit = rec_offs_nth_extern(offsets, i);
+		extern_bit = upd_ext_vec_contains(ext_vec, n_ext_vec, i);
 		
-		if (extern_bit != upd_ext_vec_contains(ext_vec, n_ext_vec, i)
+		if (UNIV_UNLIKELY(extern_bit ==
+				!rec_offs_nth_extern(offsets, i))
 		    || !dfield_data_is_binary_equal(dfield, len, data)) {
 
 			upd_field = upd_get_nth_field(update, n_diff);
@@ -826,11 +827,7 @@ row_upd_build_difference_binary(
 
 			upd_field_set_field_no(upd_field, i, index, trx);
 
-			if (upd_ext_vec_contains(ext_vec, n_ext_vec, i)) {
-				upd_field->extern_storage = TRUE;
-			} else {
-				upd_field->extern_storage = FALSE;
-			}
+			upd_field->extern_storage = extern_bit;
 
 			n_diff++;
 		}