Index: head/usr.bin/grep/util.c
===================================================================
--- head/usr.bin/grep/util.c
+++ head/usr.bin/grep/util.c
@@ -55,6 +55,9 @@
 static int	 linesqueued;
 static int	 procline(struct str *l, int);
 
+static int	 lasta;
+static bool	 ctxover;
+
 bool
 file_matching(const char *fname)
 {
@@ -212,8 +215,10 @@
 	strcpy(ln.file, fn);
 	ln.line_no = 0;
 	ln.len = 0;
+	ctxover = false;
 	linesqueued = 0;
 	tail = 0;
+	lasta = 0;
 	ln.off = -1;
 
 	for (c = 0;  c == 0 || !(lflag || qflag); ) {
@@ -235,10 +240,24 @@
 			free(f);
 			return (0);
 		}
-		/* Process the file line-by-line */
+
+		/* Process the file line-by-line, enqueue non-matching lines */
 		if ((t = procline(&ln, f->binary)) == 0 && Bflag > 0) {
-			enqueue(&ln);
-			linesqueued++;
+			/* Except don't enqueue lines that appear in -A ctx */
+			if (ln.line_no == 0 || lasta != ln.line_no) {
+				/* queue is maxed to Bflag number of lines */
+				enqueue(&ln);
+				linesqueued++;
+				ctxover = false;
+			} else {
+				/*
+				 * Indicate to procline() that we have ctx
+				 * overlap and make sure queue is empty.
+				 */
+				if (!ctxover)
+					clearqueue();
+				ctxover = true;
+			}
 		}
 		c += t;
 		if (mflag && mcount <= 0)
@@ -396,17 +415,19 @@
 	/* Dealing with the context */
 	if ((tail || c) && !cflag && !qflag && !lflag && !Lflag) {
 		if (c) {
-			if (!first && !prev && !tail && Aflag)
+			if (!first && !prev && !tail && (Bflag || Aflag) &&
+			    !ctxover)
 				printf("--\n");
 			tail = Aflag;
 			if (Bflag > 0) {
-				if (!first && !prev)
-					printf("--\n");
 				printqueue();
+				ctxover = false;
 			}
 			linesqueued = 0;
 			printline(l, ':', matches, m);
 		} else {
+			/* Print -A lines following matches */
+			lasta = l->line_no;
 			printline(l, '-', matches, m);
 			tail--;
 		}