From 18e352d24b56f04eb0b1425d879df1aed94ffdc6 Mon Sep 17 00:00:00 2001
From: kinto-b <kinto.behr@gmail.com>
Date: Mon, 15 Apr 2024 16:50:20 +1000
Subject: [PATCH] Ensure panic on length mismatch

---
 src/zip_eq_impl.rs | 11 ++++++++---
 tests/zip.rs       |  9 +++++++++
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/src/zip_eq_impl.rs b/src/zip_eq_impl.rs
index 8139c2cce..2736d3854 100644
--- a/src/zip_eq_impl.rs
+++ b/src/zip_eq_impl.rs
@@ -52,7 +52,6 @@ where
         }
     }
 
-    #[inline]
     fn fold<B, F>(self, init: B, mut f: F) -> B
     where
         Self: Sized,
@@ -60,10 +59,16 @@ where
     {
         let Self { a, mut b } = self;
 
-        a.fold(init, |acc, x| match b.next() {
+        let acc = a.fold(init, |acc, x| match b.next() {
             Some(y) => f(acc, (x, y)),
             None => panic!("itertools: .zip_eq() reached end of one iterator before the other"),
-        })
+        });
+
+        if b.next().is_some() {
+            panic!("itertools: .zip_eq() reached end of one iterator before the other")
+        }
+
+        acc
     }
 
     fn size_hint(&self) -> (usize, Option<usize>) {
diff --git a/tests/zip.rs b/tests/zip.rs
index 9efc03fc4..be886da7a 100644
--- a/tests/zip.rs
+++ b/tests/zip.rs
@@ -82,3 +82,12 @@ fn zip_eq_panic3() {
 
     zip_eq(&a, &b).fold(0, |acc, (x, y)| acc + x * y);
 }
+
+#[should_panic]
+#[test]
+fn zip_eq_panic4() {
+    let b = [1, 2];
+    let a = [1, 2, 3];
+
+    zip_eq(&a, &b).fold(0, |acc, (x, y)| acc + x * y);
+}