[1.0.1] Should never move from a signed_block in a shared_ptr

[heifner]

Should never move a signed_block that could still be used. The point of shared_ptr is shared data, you don't know if being used by something else unless you just created it. For example if still in the forkdb. Would have preferred to delete the move constructor and move operator= but unfortunately those are needed for our unused http push_block.

Resolves #737

[linh2931]

So this IS a bug as push_block in chain_plugin.cpp moves the signed block parm.

[heifner]

So this IS a bug as push_block in chain_plugin.cpp moves the signed block parm.

What push_block moves has only been seen by HTTP, so it is safe to move that one.

[heifner]

The asan test is still failing after this change. But I do think this is still a good change as we access QC's from blocks in the forkdb. At least until #719 is merged.

[ericpassmore]

Note:start
category: Other
component: Plugins/Cleos/Utils
summary: Do not move a signed block that may be used later.
Note:end

[greg7mdp]

@heifner, should you close this PR?

[heifner]

@heifner, should you close this PR?

Still need this PR. The clone() is how you make the copies. The other PR #744 is targeted to it and provides the mechanism that enforces clone() has to be called instead of std::move(*b).