[PATCH xserver] modesetting: fix conn_id termination and potential overrun by 1 byte

[Ilia Mirkin]

Noticed when porting this logic to xf86-video-nouveau, and valgrind
complained about conditional jump based on uninitialized data.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
---

memcpy sets conn_id[0..len-1], so conn_id[len] is the one that should
get the 0.

 hw/xfree86/drivers/modesetting/drmmode_display.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/xfree86/drivers/modesetting/drmmode_display.c b/hw/xfree86/drivers/modesetting/drmmode_display.c
index 939f07f8f..5c1b0ea96 100644
--- a/hw/xfree86/drivers/modesetting/drmmode_display.c
+++ b/hw/xfree86/drivers/modesetting/drmmode_display.c
@@ -2834,7 +2834,7 @@ static int parse_path_blob(drmModePropertyBlobPtr path_blob, int *conn_base_id,
     if (len + 1> 5)
         return -1;
     memcpy(conn_id, blob_data + 4, len);
-    conn_id[len + 1] = '\0';
+    conn_id[len] = '\0';
     id = strtoul(conn_id, NULL, 10);
 
     *conn_base_id = id;
-- 
2.18.1