Merge remote-tracking branch 'upstream/master' into master

Author: janmarthedal

src/biguint.rs

@@ -2423,6 +2423,10 @@ impl BigUint {
             "The radix must be within 2...256"
         );
 
+        if buf.is_empty() {
+            return Some(Zero::zero());
+        }
+
         if radix != 256 && buf.iter().any(|&b| b >= radix as u8) {
             return None;
         }
@@ -2466,6 +2470,10 @@ impl BigUint {
             "The radix must be within 2...256"
         );
 
+        if buf.is_empty() {
+            return Some(Zero::zero());
+        }
+
         if radix != 256 && buf.iter().any(|&b| b >= radix as u8) {
             return None;
         }

tests/biguint.rs

@@ -1551,6 +1551,8 @@ fn test_from_and_to_radix() {
     }
 
     assert!(BigUint::from_radix_le(&[10, 100, 10], 50).is_none());
+    assert_eq!(BigUint::from_radix_le(&[], 2), Some(BigUint::zero()));
+    assert_eq!(BigUint::from_radix_be(&[], 2), Some(BigUint::zero()));
 }
 
 #[test]