Add `-e` option to not validate empty password.

When the XF86ScreenSaver key is used to put a laptop to sleep (or to
trigger the screensaver), the key may "bounce" on resume. This is
annoying as i3lock will try to validate several empty passwords and
wait several seconds before accepting a legit password.

Some users may want to validate an empty password: PAM may rely on
other sources to unlock the screen, like the presence of a token or
the proximity of some Bluetooth device. Hence, we don't forbid this
possibility and provide an command-line option for users not willing
to validate empty passwords.

1 files changed, 10 insertions, 1 deletions

diff --git a/i3lock.c b/i3lock.c
index e5654d6..a4e0870 100644
--- a/i3lock.c
+++ b/i3lock.c
@@ -60,6 +60,7 @@ static struct xkb_keymap *xkb_keymap;
 
 cairo_surface_t *img = NULL;
 bool tile = false;
+bool ignore_empty_password = false;
 
 /* isutf, u8_dec © 2005 Jeff Bezanson, public domain */
 #define isutf(c) (((c) & 0xC0) != 0x80)
@@ -267,6 +268,10 @@ static void handle_key_press(xcb_key_press_event_t *event) {
     case XKB_KEY_Return:
     case XKB_KEY_KP_Enter:
     case XKB_KEY_XF86ScreenSaver:
+        if (ignore_empty_password && input_position == 0) {
+            clear_input();
+            return;
+        }
         password[input_position] = '\0';
         unlock_state = STATE_KEY_PRESSED;
         redraw_screen();
@@ -533,13 +538,14 @@ int main(int argc, char *argv[]) {
         {"no-unlock-indicator", no_argument, NULL, 'u'},
         {"image", required_argument, NULL, 'i'},
         {"tiling", no_argument, NULL, 't'},
+        {"ignore-empty-password", no_argument, NULL, 'e'},
         {NULL, no_argument, NULL, 0}
     };
 
     if ((username = getenv("USER")) == NULL)
         errx(1, "USER environment variable not set, please set it.\n");
 
-    while ((o = getopt_long(argc, argv, "hvnbdc:p:ui:t", longopts, &optind)) != -1) {
+    while ((o = getopt_long(argc, argv, "hvnbdc:p:ui:te", longopts, &optind)) != -1) {
         switch (o) {
         case 'v':
             errx(EXIT_SUCCESS, "version " VERSION " © 2010-2012 Michael Stapelberg");
@@ -582,6 +588,9 @@ int main(int argc, char *argv[]) {
                 errx(1, "i3lock: Invalid pointer type given. Expected one of \"win\" or \"default\".\n");
             }
             break;
+        case 'e':
+            ignore_empty_password = true;
+            break;
         case 0:
             if (strcmp(longopts[optind].name, "debug") == 0)
                 debug_mode = true;