Check if fullName is null

src/DotNet/CustomAttributeCollection.cs

@@ -37,6 +37,9 @@ public CustomAttributeCollection(int length, object context, Func<object, int, C
 		/// </summary>
 		/// <param name="fullName">Full name of custom attribute type that should be removed</param>
 		public void RemoveAll(string fullName) {
+			if (fullName == null)
+				return;
+
 			for (int i = Count - 1; i >= 0; i--) {
 				var ca = this[i];
 				if (ca is not null && fullName.EndsWith(ca.TypeName, StringComparison.Ordinal) && ca.TypeFullName == fullName)
@@ -50,6 +53,9 @@ public void RemoveAll(string fullName) {
 		/// <param name="fullName">Full name of custom attribute type</param>
 		/// <returns>A <see cref="CustomAttribute"/> or <c>null</c> if it wasn't found</returns>
 		public CustomAttribute Find(string fullName) {
+			if (fullName == null)
+				return null;
+
 			foreach (var ca in this) {
 				if (ca is not null && fullName.EndsWith(ca.TypeName, StringComparison.Ordinal) && ca.TypeFullName == fullName)
 					return ca;
@@ -64,6 +70,9 @@ public CustomAttribute Find(string fullName) {
 		/// <param name="fullName">Full name of custom attribute type</param>
 		/// <returns>All <see cref="CustomAttribute"/>s of the requested type</returns>
 		public IEnumerable<CustomAttribute> FindAll(string fullName) {
+			if (fullName == null)
+				yield break;
+
 			foreach (var ca in this) {
 				if (ca is not null && fullName.EndsWith(ca.TypeName, StringComparison.Ordinal) && ca.TypeFullName == fullName)
 					yield return ca;