Ensure BitArray fill operations do not set bits out of range (#45223)

* ensure BitArray fill operation does not produce dirty bits

* Update BitArray BinaryFormatter expected blob

src/libraries/System.Collections/src/System/Collections/BitArray.cs

@@ -52,6 +52,13 @@ public BitArray(int length, bool defaultValue)
             if (defaultValue)
             {
                 m_array.AsSpan().Fill(-1);
+
+                // clear high bit values in the last int
+                Div32Rem(length, out int extraBits);
+                if (extraBits > 0)
+                {
+                    m_array[^1] = (1 << extraBits) - 1;
+                }
             }
 
             _version = 0;
@@ -337,9 +344,20 @@ public void SetAll(bool value)
             int arrayLength = GetInt32ArrayLengthFromBitLength(Length);
             Span<int> span = m_array.AsSpan(0, arrayLength);
             if (value)
+            {
                 span.Fill(-1);
+
+                // clear high bit values in the last int
+                Div32Rem(m_length, out int extraBits);
+                if (extraBits > 0)
+                {
+                    span[^1] &= (1 << extraBits) - 1;
+                }
+            }
             else
+            {
                 span.Clear();
+            }
 
             _version++;
         }

src/libraries/System.Collections/tests/BitArray/BitArray_CtorTests.cs

@@ -66,6 +66,17 @@ public static void Ctor_Int_Bool(int length, bool defaultValue)
             Assert.False(collection.IsSynchronized);
         }
 
+        [Fact]
+        public static void Ctor_Int_Bool_ShouldNotLeaveDirtyBits()
+        {
+            BitArray bitArray = new BitArray(33, true);
+            bitArray.RightShift(31);
+
+            Assert.True(bitArray[0]);
+            Assert.True(bitArray[1]);
+            Assert.False(bitArray[2]);
+        }
+
         [Fact]
         public static void Ctor_Int_NegativeLength_ThrowsArgumentOutOfRangeException()
         {

src/libraries/System.Collections/tests/BitArray/BitArray_GetSetTests.cs

@@ -91,6 +91,18 @@ public static void SetAll(int size, bool defaultValue)
             }
         }
 
+        [Fact]
+        public static void SetAll_ShouldNotLeaveDirtyBits()
+        {
+            BitArray bitArray = new BitArray(33, false);
+            bitArray.SetAll(true);
+            bitArray.RightShift(31);
+
+            Assert.True(bitArray[0]);
+            Assert.True(bitArray[1]);
+            Assert.False(bitArray[2]);
+        }
+
         public static IEnumerable<object[]> GetEnumerator_Data()
         {
             foreach (int size in new[] { 0, 1, BitsPerByte, BitsPerByte + 1, BitsPerInt32, BitsPerInt32 + 1 })

src/libraries/System.Runtime.Serialization.Formatters/tests/BinaryFormatterTestData.cs

@@ -1264,7 +1264,7 @@ public static IEnumerable<object[]> SerializableObjects()
             yield return new object[] { point, new TypeSerializableValue[] { new TypeSerializableValue("AAEAAAD/////AQAAAAAAAAAMAgAAAHBTeXN0ZW0uUnVudGltZS5TZXJpYWxpemF0aW9uLkZvcm1hdHRlcnMuVGVzdHMsIFZlcnNpb249NC4wLjMuMCwgQ3VsdHVyZT1uZXV0cmFsLCBQdWJsaWNLZXlUb2tlbj05ZDc3Y2M3YWQzOWI2OGViBQEAAAAzU3lzdGVtLlJ1bnRpbWUuU2VyaWFsaXphdGlvbi5Gb3JtYXR0ZXJzLlRlc3RzLlBvaW50AgAAAAFYAVkAAAgIAgAAAAEAAAACAAAACw==", TargetFrameworkMoniker.netcoreapp20), new TypeSerializableValue("AAEAAAD/////AQAAAAAAAAAMAgAAAHBTeXN0ZW0uUnVudGltZS5TZXJpYWxpemF0aW9uLkZvcm1hdHRlcnMuVGVzdHMsIFZlcnNpb249NC4wLjMuMCwgQ3VsdHVyZT1uZXV0cmFsLCBQdWJsaWNLZXlUb2tlbj05ZDc3Y2M3YWQzOWI2OGViBQEAAAAzU3lzdGVtLlJ1bnRpbWUuU2VyaWFsaXphdGlvbi5Gb3JtYXR0ZXJzLlRlc3RzLlBvaW50AgAAAAFYAVkAAAgIAgAAAAEAAAACAAAACw==", TargetFrameworkMoniker.netfx461) } };
 
             // Collections
-            yield return new object[] { new System.Collections.BitArray(5, true), new TypeSerializableValue[] { new TypeSerializableValue("AAEAAAD/////AQAAAAAAAAAEAQAAABtTeXN0ZW0uQ29sbGVjdGlvbnMuQml0QXJyYXkDAAAAB21fYXJyYXkIbV9sZW5ndGgIX3ZlcnNpb24HAAAICAgJAgAAAAUAAAAAAAAADwIAAAABAAAACP////8L", TargetFrameworkMoniker.netcoreapp20), new TypeSerializableValue("AAEAAAD/////AQAAAAAAAAAEAQAAABtTeXN0ZW0uQ29sbGVjdGlvbnMuQml0QXJyYXkDAAAAB21fYXJyYXkIbV9sZW5ndGgIX3ZlcnNpb24HAAAICAgJAgAAAAUAAAAAAAAADwIAAAABAAAACP////8L", TargetFrameworkMoniker.netfx461) } };
+            yield return new object[] { new System.Collections.BitArray(5, true), new TypeSerializableValue[] { new TypeSerializableValue("AAEAAAD/////AQAAAAAAAAAEAQAAABtTeXN0ZW0uQ29sbGVjdGlvbnMuQml0QXJyYXkDAAAAB21fYXJyYXkIbV9sZW5ndGgIX3ZlcnNpb24HAAAICAgJAgAAAAUAAAAAAAAADwIAAAABAAAACB8AAAAL", TargetFrameworkMoniker.netcoreapp20), new TypeSerializableValue("AAEAAAD/////AQAAAAAAAAAEAQAAABtTeXN0ZW0uQ29sbGVjdGlvbnMuQml0QXJyYXkDAAAAB21fYXJyYXkIbV9sZW5ndGgIX3ZlcnNpb24HAAAICAgJAgAAAAUAAAAAAAAADwIAAAABAAAACP////8L", TargetFrameworkMoniker.netfx461) } };
             yield return new object[] { new System.Collections.ArrayList(Enumerable.Range(1, 40).ToList()), new TypeSerializableValue[] { new TypeSerializableValue("AAEAAAD/////AQAAAAAAAAAEAQAAABxTeXN0ZW0uQ29sbGVjdGlvbnMuQXJyYXlMaXN0AwAAAAZfaXRlbXMFX3NpemUIX3ZlcnNpb24FAAAICAkCAAAAKAAAAAEAAAAQAgAAACgAAAAICAEAAAAICAIAAAAICAMAAAAICAQAAAAICAUAAAAICAYAAAAICAcAAAAICAgAAAAICAkAAAAICAoAAAAICAsAAAAICAwAAAAICA0AAAAICA4AAAAICA8AAAAICBAAAAAICBEAAAAICBIAAAAICBMAAAAICBQAAAAICBUAAAAICBYAAAAICBcAAAAICBgAAAAICBkAAAAICBoAAAAICBsAAAAICBwAAAAICB0AAAAICB4AAAAICB8AAAAICCAAAAAICCEAAAAICCIAAAAICCMAAAAICCQAAAAICCUAAAAICCYAAAAICCcAAAAICCgAAAAL", TargetFrameworkMoniker.netcoreapp20), new TypeSerializableValue("AAEAAAD/////AQAAAAAAAAAEAQAAABxTeXN0ZW0uQ29sbGVjdGlvbnMuQXJyYXlMaXN0AwAAAAZfaXRlbXMFX3NpemUIX3ZlcnNpb24FAAAICAkCAAAAKAAAAAEAAAAQAgAAACgAAAAICAEAAAAICAIAAAAICAMAAAAICAQAAAAICAUAAAAICAYAAAAICAcAAAAICAgAAAAICAkAAAAICAoAAAAICAsAAAAICAwAAAAICA0AAAAICA4AAAAICA8AAAAICBAAAAAICBEAAAAICBIAAAAICBMAAAAICBQAAAAICBUAAAAICBYAAAAICBcAAAAICBgAAAAICBkAAAAICBoAAAAICBsAAAAICBwAAAAICB0AAAAICB4AAAAICB8AAAAICCAAAAAICCEAAAAICCIAAAAICCMAAAAICCQAAAAICCUAAAAICCYAAAAICCcAAAAICCgAAAAL", TargetFrameworkMoniker.netfx461) } };
             yield return new object[] { new System.Collections.ArrayList(10), new TypeSerializableValue[] { new TypeSerializableValue("AAEAAAD/////AQAAAAAAAAAEAQAAABxTeXN0ZW0uQ29sbGVjdGlvbnMuQXJyYXlMaXN0AwAAAAZfaXRlbXMFX3NpemUIX3ZlcnNpb24FAAAICAkCAAAAAAAAAAAAAAAQAgAAAAoAAAANCgs=", TargetFrameworkMoniker.netcoreapp20), new TypeSerializableValue("AAEAAAD/////AQAAAAAAAAAEAQAAABxTeXN0ZW0uQ29sbGVjdGlvbnMuQXJyYXlMaXN0AwAAAAZfaXRlbXMFX3NpemUIX3ZlcnNpb24FAAAICAkCAAAAAAAAAAAAAAAQAgAAAAoAAAANCgs=", TargetFrameworkMoniker.netfx461) } };
             yield return new object[] { new System.Collections.Comparer(new CultureInfo("")), new TypeSerializableValue[] { new TypeSerializableValue("AAEAAAD/////AQAAAAAAAAAEAQAAABtTeXN0ZW0uQ29sbGVjdGlvbnMuQ29tcGFyZXIBAAAAC0NvbXBhcmVJbmZvAyBTeXN0ZW0uR2xvYmFsaXphdGlvbi5Db21wYXJlSW5mbwkCAAAABAIAAAAgU3lzdGVtLkdsb2JhbGl6YXRpb24uQ29tcGFyZUluZm8DAAAABm1fbmFtZQ1tX1NvcnRWZXJzaW9uB2N1bHR1cmUBAwAgU3lzdGVtLkdsb2JhbGl6YXRpb24uU29ydFZlcnNpb24IBgMAAAAACn8AAAAL", TargetFrameworkMoniker.netcoreapp20), new TypeSerializableValue("AAEAAAD/////AQAAAAAAAAAEAQAAABtTeXN0ZW0uQ29sbGVjdGlvbnMuQ29tcGFyZXIBAAAAC0NvbXBhcmVJbmZvAyBTeXN0ZW0uR2xvYmFsaXphdGlvbi5Db21wYXJlSW5mbwkCAAAABAIAAAAgU3lzdGVtLkdsb2JhbGl6YXRpb24uQ29tcGFyZUluZm8EAAAABm1fbmFtZQl3aW4zMkxDSUQHY3VsdHVyZQ1tX1NvcnRWZXJzaW9uAQAAAwgIIFN5c3RlbS5HbG9iYWxpemF0aW9uLlNvcnRWZXJzaW9uBgMAAAAAAAAAAH8AAAAKCw==", TargetFrameworkMoniker.netfx461) } };