$OpenBSD: patch-common_rcslib_c,v 1.2 2014/06/25 17:54:07 naddy Exp $
--- common/rcslib.c.orig	Mon Jul 18 16:34:30 2005
+++ common/rcslib.c	Wed Jun 25 00:48:47 2014
@@ -64,6 +64,7 @@ static const struct rcs_keyword rcs_keywords[] = {
 	{ "strict",	6 },
 	{ "symbols",	7 },
 	{ "text",	4 },
+	{ "commitid",	8 },
 	{ NULL,		0 }
 };
 
@@ -83,7 +84,8 @@ enum {
 	RCS_STATE,
 	RCS_STRICT,
 	RCS_SYMBOLS,
-	RCS_TEXT
+	RCS_TEXT,
+	RCS_COMMITID
 };
 
 #define	RCS_SKIP(p, e)			\
@@ -579,6 +581,40 @@ rcslib_parse_delta(struct rcslib_file *rcs, char *sp, 
 			return (NULL);
 		}
 
+		/* commitid id; */
+		rcskey = &rcs_keywords[RCS_COMMITID];
+		if ((sp + rcskey->namelen > bp) ||
+		    (memcmp(sp, rcskey->name, rcskey->namelen) != 0)) {
+			rev->commitid.i_id = NULL;
+			rev->commitid.i_len = 0;
+		} else {
+			sp += rcskey->namelen;
+
+			p = sp;
+			RCS_SKIP_NORET(sp, bp)
+			if ((sp > bp) || (sp == p)) {
+			    free(delta->rd_rev);
+			    return (NULL);
+			}
+
+			if ((sp = rcslib_parse_id(sp, bp, &rev->commitid)) == NULL) {
+				free(delta->rd_rev);
+				return (NULL);
+			}
+
+			RCS_SKIP_NORET(sp, bp)
+			if ((sp > bp) || (*sp++ != ';')) {
+				free(delta->rd_rev);
+				return (NULL);
+			}
+
+			RCS_SKIP_NORET(sp, bp)
+			if (sp > bp) {
+				free(delta->rd_rev);
+				return (NULL);
+			}
+		}
+
 		/* { newphrase }* */
 		p = sp;
 		if ((sp = rcslib_parse_newphrase(sp, bp)) == NULL) {
@@ -1522,10 +1558,24 @@ rcslib_write_delta(int fd, const struct rcslib_revisio
 	iov[0].iov_len = 7;
 	iov[1].iov_base = rev->next.n_str;
 	iov[1].iov_len = rev->next.n_len;
-	iov[2].iov_base = ";\n\n";
-	iov[2].iov_len = 3;
-	len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len;
-	if ((wn = writev(fd, iov, 3)) == -1)
+	iov[2].iov_base = ";\n";
+	iov[2].iov_len = 2;
+	if (rev->commitid.i_len > 0) {
+		iov[3].iov_base ="commitid\t";
+		iov[3].iov_len = 9;
+		iov[4].iov_base = rev->commitid.i_id;
+		iov[4].iov_len = rev->commitid.i_len;
+		iov[5].iov_base = ";\n\n";
+		iov[5].iov_len = 3;
+	} else {
+		iov[3].iov_base = "\n";
+		iov[3].iov_len = 1;
+		iov[4].iov_base = iov[5].iov_base = NULL;
+		iov[4].iov_len = iov[5].iov_len = 0;
+	}
+	len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len +
+	      iov[3].iov_len + iov[4].iov_len + iov[5].iov_len;
+	if ((wn = writev(fd, iov, 6)) == -1)
 		return (false);
 	if ((size_t)wn != len)
 		return (false);