Description

Both LinkSuffix and LinkPrefix have an optimization around zero length chunk to avoid unnecessary chaining:

// avoid chaining empty chunks:
if (prefix.Count == 0)
{
    return;
}

The issue is that LinkPrefix/Suffix effectively pass ownership of the BlobBuilder to the receiver. In the non-zero case it's put into the chain of chunks and freeing the head will free the time. In the zero case though the suffix / prefix is never freed. That makes managing pools difficult:

BlobBuilder b1 = GetBuilder1();
BlobBuilder b2 = GetBuilder2();
b1.LinkSuffix(b2);
b1.Free(); // Did that free b2 or not? Depends on length of b2

Reproduction Steps

var b1 = PooledBlobBuilder.GetInstance();
var b2 = PooledBlobBuilder.GetInstance();
var b3 = PooledBlobBuilder.GetInstance();
b1.WriteBytes(1, 1);
b2.WriteBytes(1, 1);
b1.LinkSuffix(b2);
b1.LinkSuffix(b3);
b1.Free();

Expected behavior

All of the instances are freed

Actual behavior

The b3 instance is not freed cause it was discarded in LinkSuffix for having a zero length.

Regression?

No.

Known Workarounds

Add LinkSuffixSmart / LinkPrefixSmart extension methods that do the zero check.

Configuration

No response

Other information

No response