From fe5edad1fcd60d94bc45ca49f94636eeecae210d Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicm@openbsd.org>
Date: Thu, 2 Jul 2009 16:15:43 +0000
Subject: [PATCH] Fix two copy/paste bugs: forbid zero-length buffers to
 prevent a fatal error when trying to paste them, found by me, and
 miscalculation of the start/end causing random fatal errors when copying in
 copy-mode, reported by sthen.

ok sthen "put it in" deraadt
---
 cmd-paste-buffer.c | 2 +-
 paste.c            | 3 +++
 window-copy.c      | 2 +-
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/cmd-paste-buffer.c b/cmd-paste-buffer.c
index 35472d3d..3f4cfe2e 100644
--- a/cmd-paste-buffer.c
+++ b/cmd-paste-buffer.c
@@ -63,7 +63,7 @@ cmd_paste_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 		}
 	}
 
-	if (pb != NULL)
+	if (pb != NULL && *pb->data != '\0')
 		buffer_write(w->active->out, pb->data, strlen(pb->data));
 
 	/* Delete the buffer if -d. */
diff --git a/paste.c b/paste.c
index 3644381c..981385e9 100644
--- a/paste.c
+++ b/paste.c
@@ -101,6 +101,9 @@ paste_add(struct paste_stack *ps, char *data, u_int limit)
 {
 	struct paste_buffer	*pb;
 
+	if (*data == '\0')
+		return;
+
 	while (ARRAY_LENGTH(ps) >= limit)
 		ARRAY_TRUNC(ps, 1);
 
diff --git a/window-copy.c b/window-copy.c
index dc2a4d45..a64be760 100644
--- a/window-copy.c
+++ b/window-copy.c
@@ -423,7 +423,7 @@ window_copy_copy_selection(struct window_pane *wp, struct client *c)
 	/* Find start and end. */
 	xx = data->cx + data->ox;
 	yy = screen_hsize(&wp->base) + data->cy - data->oy;
-	if (xx < data->selx || (yy == data->sely && xx < data->selx)) {
+	if (yy < data->sely || (yy == data->sely && xx < data->selx)) {
 		sx = xx; sy = yy;
 		ex = data->selx; ey = data->sely;
 	} else {