Merge branch 'dev' into dankrad-custody-256bit

# Conflicts:
#	specs/phase1/beacon-chain.md

specs/phase0/fork-choice.md

@@ -371,15 +371,19 @@ def on_block(store: Store, signed_block: SignedBeaconBlock) -> None:
     # Update finalized checkpoint
     if state.finalized_checkpoint.epoch > store.finalized_checkpoint.epoch:
         store.finalized_checkpoint = state.finalized_checkpoint
-        finalized_slot = compute_start_slot_at_epoch(store.finalized_checkpoint.epoch)
 
-        # Update justified if new justified is later than store justified
-        # or if store justified is not in chain with finalized checkpoint
-        if (
-            state.current_justified_checkpoint.epoch > store.justified_checkpoint.epoch
-            or get_ancestor(store, store.justified_checkpoint.root, finalized_slot) != store.finalized_checkpoint.root
-        ):
-            store.justified_checkpoint = state.current_justified_checkpoint
+        # Potentially update justified if different from store
+        if store.justified_checkpoint != state.current_justified_checkpoint:
+            # Update justified if new justified is later than store justified
+            if state.current_justified_checkpoint.epoch > store.justified_checkpoint.epoch:
+                store.justified_checkpoint = state.current_justified_checkpoint
+                return
+
+            # Update justified if store justified is not in chain with finalized checkpoint
+            finalized_slot = compute_start_slot_at_epoch(store.finalized_checkpoint.epoch)
+            ancestor_at_finalized_slot = get_ancestor(store, store.justified_checkpoint.root, finalized_slot)
+            if ancestor_at_finalized_slot != store.finalized_checkpoint.root:
+                store.justified_checkpoint = state.current_justified_checkpoint
 ```
 
 #### `on_attestation`

specs/phase1/beacon-chain.md

@@ -12,6 +12,11 @@
 - [Custom types](#custom-types)
 - [Configuration](#configuration)
   - [Misc](#misc)
+  - [Shard block configs](#shard-block-configs)
+  - [Gwei values](#gwei-values)
+  - [Initial values](#initial-values)
+  - [Time parameters](#time-parameters)
+  - [Domain types](#domain-types)
 - [Updated containers](#updated-containers)
   - [Extended `AttestationData`](#extended-attestationdata)
   - [Extended `Attestation`](#extended-attestation)
@@ -103,11 +108,39 @@ Configuration is not namespaced. Instead it is strictly an extension;
 
 ### Misc
 
-| Name | Value | Unit | Duration |
-| - | - | - | - | 
-| `MAX_SHARDS` | `2**10` (= 1024) | - | - |
-| `ONLINE_PERIOD` | `OnlineEpochs(2**3)` (= 8) | online epochs | ~51 min |
+| Name | Value |
+| - | - | 
+| `MAX_SHARDS` | `2**10` (= 1024) |
 | `LIGHT_CLIENT_COMMITTEE_SIZE` | `2**7` (= 128) |
+| `GASPRICE_ADJUSTMENT_COEFFICIENT` | `2**3` (= 8) | 
+
+### Shard block configs
+
+| Name | Value |
+| - | - |
+| `MAX_SHARD_BLOCK_SIZE` | `2**20` (= 1,048,576) | 
+| `TARGET_SHARD_BLOCK_SIZE` | `2**18` (= 262,144) | 
+| `SHARD_BLOCK_OFFSETS` | `[1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233]` | 
+| `MAX_SHARD_BLOCKS_PER_ATTESTATION` | `len(SHARD_BLOCK_OFFSETS)` | 
+
+### Gwei values
+
+| Name | Value |
+| - | - |
+| `MAX_GASPRICE` | `Gwei(2**14)` (= 16,384) | Gwei | 
+| `MIN_GASPRICE` | `Gwei(2**3)` (= 8) | Gwei | 
+
+### Initial values
+
+| Name | Value |
+| - | - |
+| `NO_SIGNATURE` | `BLSSignature(b'\x00' * 96)` | 
+
+### Time parameters
+
+| Name | Value | Unit | Duration |
+| - | - | :-: | :-: |
+| `ONLINE_PERIOD` | `OnlineEpochs(2**3)` (= 8) | online epochs | ~51 mins |
 | `LIGHT_CLIENT_COMMITTEE_PERIOD` | `Epoch(2**8)` (= 256) | epochs | ~27 hours |
 | `MAX_SHARD_BLOCK_SIZE` | `2**20` (= 1,048,576) | bytes | - |
 | `TARGET_SHARD_BLOCK_SIZE` | `2**18` (= 262,144) | bytes | - |
@@ -124,6 +157,14 @@ Configuration is not namespaced. Instead it is strictly an extension;
 | `CUSTODY_RESPONSE_DEPTH` | `ceillog2(MAX_SHARD_BLOCK_SIZE // BYTES_PER_CUSTODY_CHUNK)` | - | - |
 | `NO_SIGNATURE` | `BLSSignature(b'\x00' * 96)` | | |
 
+### Domain types
+
+| Name | Value |
+| - | - |
+| `DOMAIN_SHARD_PROPOSAL` | `DomainType('0x80000000')` | 
+| `DOMAIN_SHARD_COMMITTEE` | `DomainType('0x81000000')` | 
+| `DOMAIN_LIGHT_CLIENT` | `DomainType('0x82000000')` | 
+
 ## Updated containers
 
 The following containers have updated definitions in Phase 1.