Convert.TryToHexString{Lower} does not check the length of destination correct

[universorum]

Description

Convert.TryToHexString{Lower} will allow the destination that smaller than actual length and will NOT allow what is bigger than 2x actual length.

Reproduction Steps

Span<byte> hashBuffer  = stackalloc byte[16];

Span<char> biggerThanDoubleLength = stackalloc char[33];
Debug.Assert(Convert.TryToHexString(hashBuffer, biggerThanDoubleLength, out _) == false);

Span<char> lessThanLength = stackalloc char[31]; 
Debug.Assert(Convert.TryToHexStringLower(hashBuffer, lessThanLength, out var length));
Debug.Assert(length == 32);

Console.WriteLine("done");

Expected behavior

The function may return false when the size of destination is smaller than 2x source and working when destination is bigger than 2x source.

Actual behavior

The function will return true when the size of destination is smaller than 2x source with proper out variable charsWritten and will NOT working when destination is bigger than 2x source.

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

It look like 2 variable is reversed.

runtime/src/libraries/System.Private.CoreLib/src/System/Convert.cs

Line 3102 in 1c4c009

else if (source.Length > int.MaxValue / 2 || destination.Length > source.Length * 2)

runtime/src/libraries/System.Private.CoreLib/src/System/Convert.cs

Line 3179 in 1c4c009

else if (source.Length > int.MaxValue / 2 || destination.Length > source.Length * 2)

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[danmoseley]

Would you like to investigate a bit? Edit: you already did. Would you like to offer a PR with a test? Thanks for the report