Fix FlattenCompat::{next, next_back}

rust-lang · Mar 16, 2020 · cff1182 · cff1182
1 parent 16a23e7
commit cff1182
Showing 1 changed file with 6 additions and 4 deletions.
diff --git a/src/libcore/iter/adapters/flatten.rs b/src/libcore/iter/adapters/flatten.rs
@@ -264,8 +264,9 @@ where
     fn next(&mut self) -> Option<U::Item> {
         loop {
             if let Some(ref mut inner) = self.frontiter {
-                if let elt @ Some(_) = inner.next() {
-                    return elt;
+                match inner.next() {
+                    None => self.frontiter = None,
+                    elt @ Some(_) => return elt,
                 }
             }
             match self.iter.next() {
@@ -351,8 +352,9 @@ where
     fn next_back(&mut self) -> Option<U::Item> {
         loop {
             if let Some(ref mut inner) = self.backiter {
-                if let elt @ Some(_) = inner.next_back() {
-                    return elt;
+                match inner.next_back() {
+                    None => self.backiter = None,
+                    elt @ Some(_) => return elt,
                 }
             }
             match self.iter.next_back() {