From: Tobias Stoeckmann <tobias@stoeckmann.org>
Date: Sat, 25 Mar 2017 20:16:01 +0000 (+0100)
Subject: Properly clear the last entered character
X-Git-Url: https://git.danieliu.xyz/?a=commitdiff_plain;h=35633d45672d14bd798c478c45d1a17064701aa9;p=slock.git

Properly clear the last entered character

When enter is pressed, passwd[len] will be set to '\0'. Pressing
backspace is supposed to remove the last entered character.

But currently, the clearing has an off-by-one, as in setting
passwd[len] to '\0' just like enter would do.

You can also verify it by imagining len=1 and that it's impossible to
clear passwd[0] by pressing backspace with the current code.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
---

diff --git a/slock.c b/slock.c
index d55eb3d..5ae738c 100644
--- a/slock.c
+++ b/slock.c
@@ -177,7 +177,7 @@ readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
 				break;
 			case XK_BackSpace:
 				if (len)
-					passwd[len--] = '\0';
+					passwd[--len] = '\0';
 				break;
 			default:
 				if (num && !iscntrl((int)buf[0]) &&