ConcurrentStack.PushRange(T[]) throws an ArgumentOutOfRangeException on empty T[]

[megazyz]

Description

ConcurrentStack<T>.PushRange(T[]) throws an ArgumentOutOfRangeException when T[] is an empty array. The exception message is 'The startIndex argument must be greater than or equal to zero.'.

• This behavior is not documented
• It should do nothing instead of throwing an exception, like List<T>.AddRange(IEnumerable<T>) does

Reproduction Steps

new ConcurrentStack<int>().PushRange(Array.Empty<int>());

Expected behavior

It should not throw an exception.

Actual behavior

It throws an ArgumentOutOfRangeException: 'The startIndex argument must be greater than or equal to zero.'

Regression?

No response

Known Workarounds

Check the array for Length > 0 before calling ConcurrentStack<T>.PushRange(T[]).

Configuration

.NET 6.0.100

Other information

No response

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Issue Details

---

Description

ConcurrentStack<T>.PushRange(T[]) throws an ArgumentOutOfRangeException when T[] is an empty array. The exception message is 'The startIndex argument must be greater than or equal to zero.'.

• This behavior is not documented
• It should do nothing instead of throwing an exception, like List<T>.AddRange(IEnumerable<T>) does

Reproduction Steps

new ConcurrentStack<int>().PushRange(Array.Empty<int>());

Expected behavior

It should not throw an exception.

Actual behavior

It throws an ArgumentOutOfRangeException: 'The startIndex argument must be greater than or equal to zero.'

Regression?

No response

Known Workarounds

Check the array for Length > 0 before calling ConcurrentStack<T>.PushRange(T[]).

Configuration

.NET 6.0.100

Other information

No response

Author:	megazyz
Assignees:	-
Labels:	area-System.Collections, untriaged
Milestone:	-

[martincostello]

Looks like the argument validation happens before the zero length special case:

runtime/src/libraries/System.Collections.Concurrent/src/System/Collections/Concurrent/ConcurrentStack.cs

Lines 346 to 350 in 12a8819

	ValidatePushPopRangeInput(items, startIndex, count);
	// No op if the count is zero
	if (count == 0)
	return;

which throws because startIndex and items.Length are equal:

runtime/src/libraries/System.Collections.Concurrent/src/System/Collections/Concurrent/ConcurrentStack.cs

Lines 412 to 416 in 12a8819

	int length = items.Length;
	if (startIndex >= length || startIndex < 0)
	{
	throw new ArgumentOutOfRangeException(nameof(startIndex), SR.ConcurrentStack_PushPopRange_StartOutOfRange);
	}

[martincostello]

Proposed fix: #62126