From 0237ff105f56fac3dae552496de44a26ed7ea5fd Mon Sep 17 00:00:00 2001
From: Virgil Dupras <hsoft@hardcoded.net>
Date: Sun, 21 Jul 2019 19:43:45 -0400
Subject: [PATCH] ed: fix 'd' going crazy when deleting last lines of buf

---
 apps/ed/buf.asm | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/apps/ed/buf.asm b/apps/ed/buf.asm
index d907611..988f191 100644
--- a/apps/ed/buf.asm
+++ b/apps/ed/buf.asm
@@ -111,6 +111,13 @@ bufDelLines:
 	pop	de	; <-- lvl 2
 	pop	hl	; <-- lvl 1
 	; Line count updated!
+	; One other thing... is BC zero? Because if it is, then we shouldn't
+	; call ldir (otherwise we're on for a veeeery long loop), BC=0 means
+	; that only last lines were deleted. nothing to do.
+	ld	a, b
+	or	c
+	ret	z	; BC==0, return
+
 	; let's have invert HL and DE to match LDIR's signature
 	ex	de, hl
 	; At this point we have higher index in HL, lower index in DE and number