Implement "addr1,+N" ranges - not dissimilar to grep's -A switch.

PR:		134856
Submitted by:	Jeremie Le Hen - jeremie at le-hen dot org

1 files changed, 20 insertions, 13 deletions

diff --git a/usr.bin/sed/process.c b/usr.bin/sed/process.c
index a29fe0e..5e2618a 100644
--- a/usr.bin/sed/process.c
+++ b/usr.bin/sed/process.c
@@ -275,8 +275,8 @@ new:		if (!nflag && !pd)
 	    (a)->type == AT_LINE ? linenum == (a)->u.l : lastline())
 
 /*
- * Return TRUE if the command applies to the current line.  Sets the inrange
- * flag to process ranges.  Interprets the non-select (``!'') flag.
+ * Return TRUE if the command applies to the current line.  Sets the start
+ * line for process ranges.  Interprets the non-select (``!'') flag.
  */
 static __inline int
 applies(struct s_command *cp)
@@ -287,18 +287,22 @@ applies(struct s_command *cp)
 	if (cp->a1 == NULL && cp->a2 == NULL)
 		r = 1;
 	else if (cp->a2)
-		if (cp->inrange) {
+		if (cp->startline > 0) {
 			if (MATCH(cp->a2)) {
-				cp->inrange = 0;
+				cp->startline = 0;
 				lastaddr = 1;
 				r = 1;
-			} else if (cp->a2->type == AT_LINE &&
-				   linenum > cp->a2->u.l) {
+			} else if (linenum - cp->startline <= cp->a2->u.l)
+				r = 1;
+			else if ((cp->a2->type == AT_LINE &&
+				   linenum > cp->a2->u.l) ||
+				   (cp->a2->type == AT_RELLINE &&
+				   linenum - cp->startline > cp->a2->u.l)) {
 				/*
 				 * We missed the 2nd address due to a branch,
 				 * so just close the range and return false.
 				 */
-				cp->inrange = 0;
+				cp->startline = 0;
 				r = 0;
 			} else
 				r = 1;
@@ -308,12 +312,15 @@ applies(struct s_command *cp)
 			 * equal to the line number first selected, only
 			 * one line shall be selected.
 			 *	-- POSIX 1003.2
+			 * Likewise if the relative second line address is zero.
 			 */
-			if (cp->a2->type == AT_LINE &&
-			    linenum >= cp->a2->u.l)
+			if ((cp->a2->type == AT_LINE &&
+			    linenum >= cp->a2->u.l) ||
+			    (cp->a2->type == AT_RELLINE && cp->a2->u.l == 0))
 				lastaddr = 1;
-			else
-				cp->inrange = 1;
+			else {
+				cp->startline = linenum;
+			}
 			r = 1;
 		} else
 			r = 0;
@@ -331,11 +338,11 @@ resetstate(void)
 	struct s_command *cp;
 
 	/*
-	 * Reset all inrange markers.
+	 * Reset all in-range markers.
 	 */
 	for (cp = prog; cp; cp = cp->code == '{' ? cp->u.c : cp->next)
 		if (cp->a2)
-			cp->inrange = 0;
+			cp->startline = 0;
 
 	/*
 	 * Clear out the hold space.