Re: ReadRecentBuffer() is broken for local buffer

        if (BufferIsLocal(recent_buffer))
        {
-               bufHdr = GetBufferDescriptor(-recent_buffer - 1);
+               bufHdr = GetLocalBufferDescriptor(-recent_buffer - 1);

Aha, we're using the wrong buffer descriptors here. Currently this
function is only called in XLogReadBufferExtended(), so the branch for
local buffer cannot be reached. Maybe that's why it is not identified

The code after that looks suspicious, too. It increases the usage count
even if the buffer was already pinned. That's different from what it
does for a shared buffer, and different from LocalBufferAlloc(). That's
pretty harmless, just causes the usage count to be bumped more
frequently, but I don't think it was intentional. The ordering of
bumping the usage count, the local ref count, and registration in the
resource owner are different too. As far as I can see, that makes no
difference, but I think we should keep this code as close as possible to
similar code used elsewhere, unless there's a particular reason to differ.