Add forgotted return for invalid prposal signatures.

Some cleanup and TODO updates.

code/actors/src/consensus.rs

@@ -215,9 +215,7 @@ where
                     return Ok(());
                 };
 
-                // TODO - proposals with invalid signatures should be dropped.
-                // For well signed we should validate the proposal against the block parts (if all received).
-                // Add `valid()` to Context.
+                // TODO - verify that the proposal was signed by the proposer for the height and round, drop otherwise.
                 let proposal = &signed_proposal.proposal;
                 let proposal_height = proposal.height();
                 let proposal_round = proposal.round();
@@ -231,7 +229,8 @@ where
                         proposal_height,
                         proposal_round,
                         proposal.value()
-                    )
+                    );
+                    return Ok(());
                 }
                 assert!(proposal_height == state.driver.height());
 
@@ -277,6 +276,7 @@ where
                     return Ok(());
                 }
 
+                // TODO - verify that the proposal was signed by the proposer for the height and round, drop otherwise.
                 self.proposal_builder.cast(ProposalBuilderMsg::BlockPart {
                     block_part: signed_block_part.block_part,
                     reply_to: myself.clone(),

code/actors/src/util/value_builder.rs

@@ -252,6 +252,12 @@ pub mod test {
         }
     }
 
+    // This is a temporary store implementation for block parts
+    // TODO-s:
+    // - make it context generic
+    // - add Address to key
+    //   - not sure if this is required as consensus should verify that only the parts signed by the proposer for
+    //     the height and round should be forwarded here (see the TODOs in consensus)
     #[derive(Clone, Debug, PartialEq, Eq)]
     pub struct PartStore {
         pub map: BTreeMap<(Height, Round, u64), BlockPart>,