From d0b3416a54a65fe090d63d608a761543ba4b3291 Mon Sep 17 00:00:00 2001
From: realaravinth <realaravinth@batsense.net>
Date: Mon, 7 Jun 2021 14:23:43 +0530
Subject: [PATCH] levels: index out of bounds

---
 src/defense.rs  | 12 ++++++++----
 src/mcaptcha.rs |  2 +-
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/defense.rs b/src/defense.rs
index f127c85..32c39d1 100644
--- a/src/defense.rs
+++ b/src/defense.rs
@@ -183,14 +183,14 @@ impl Defense {
     /// tighten up defense. Increases defense level by a factor of one.
     /// When defense is at max level, calling this method will have no effect
     pub fn tighten_up(&mut self) {
-        if self.current_visitor_threshold != self.levels.len() - 1 {
+        if self.current_visitor_threshold < self.levels.len() - 1 {
             self.current_visitor_threshold += 1;
         }
     }
     /// Loosen up defense. Decreases defense level by a factor of one.
     /// When defense is at the lowest level, calling this method will have no effect.
     pub fn loosen_up(&mut self) {
-        if self.current_visitor_threshold != 0 {
+        if self.current_visitor_threshold > 0 {
             self.current_visitor_threshold -= 1;
         }
     }
@@ -206,8 +206,12 @@ impl Defense {
     }
 
     /// Get current level's  visitor threshold
-    pub fn visitor_threshold(&self) -> u32 {
-        self.levels[self.current_visitor_threshold].visitor_threshold
+    pub fn visitor_threshold(&self) -> Option<u32> {
+        if let Some(level) = self.levels.get(self.current_visitor_threshold) {
+            Some(level.visitor_threshold)
+        } else {
+            None
+        }
     }
 }
 
diff --git a/src/mcaptcha.rs b/src/mcaptcha.rs
index a5919c2..d653c53 100644
--- a/src/mcaptcha.rs
+++ b/src/mcaptcha.rs
@@ -83,7 +83,7 @@ impl MCaptcha {
     #[inline]
     pub fn add_visitor(&mut self) {
         self.visitor_threshold += 1;
-        if self.visitor_threshold > self.defense.visitor_threshold() {
+        if self.visitor_threshold > self.defense.visitor_threshold().unwrap() {
             self.defense.tighten_up();
         } else {
             self.defense.loosen_up();