Backporting to stable (#6060)

* --reseal-on-uncle (#5940)

* --reseal-on-uncle

* Optimized uncle check

* Additional uncle check

* Updated comment

* v1.6.9

* CLI: Export error message and less verbose peer counter. (#5870)

* Removed numbed of active connections from informant

* Print error message when fatdb is required

* Remove peers from UI

parity/cli/mod.rs

@@ -224,6 +224,8 @@ usage! {
 			or |c: &Config| otry!(c.mining).force_sealing.clone(),
 		flag_reseal_on_txs: String = "own",
 			or |c: &Config| otry!(c.mining).reseal_on_txs.clone(),
+		flag_reseal_on_uncle: bool = false,
+			or |c: &Config| otry!(c.mining).reseal_on_uncle.clone(),
 		flag_reseal_min_period: u64 = 2000u64,
 			or |c: &Config| otry!(c.mining).reseal_min_period.clone(),
 		flag_work_queue_size: usize = 20usize,
@@ -461,6 +463,7 @@ struct Mining {
 	author: Option<String>,
 	engine_signer: Option<String>,
 	force_sealing: Option<bool>,
+	reseal_on_uncle: Option<bool>,
 	reseal_on_txs: Option<String>,
 	reseal_min_period: Option<u64>,
 	work_queue_size: Option<usize>,
@@ -705,6 +708,7 @@ mod tests {
 			flag_force_sealing: true,
 			flag_reseal_on_txs: "all".into(),
 			flag_reseal_min_period: 4000u64,
+			flag_reseal_on_uncle: false,
 			flag_work_queue_size: 20usize,
 			flag_tx_gas_limit: Some("6283184".into()),
 			flag_tx_time_limit: Some(100u64),
@@ -904,6 +908,7 @@ mod tests {
 				engine_signer: Some("0xdeadbeefcafe0000000000000000000000000001".into()),
 				force_sealing: Some(true),
 				reseal_on_txs: Some("all".into()),
+				reseal_on_uncle: None,
 				reseal_min_period: Some(4000),
 				work_queue_size: None,
 				relay_set: None,

parity/cli/usage.txt

@@ -221,6 +221,9 @@ Sealing/Mining Options:
                                  ext - reseal only on a new external transaction;
                                  all - reseal on all new transactions
                                  (default: {flag_reseal_on_txs}).
+  --reseal-on-uncle              Force the node to author new blocks when a new uncle
+                                 block is imported.
+                                 (default: {flag_reseal_on_uncle})
   --reseal-min-period MS         Specify the minimum time between reseals from
                                  incoming transactions. MS is time measured in
                                  milliseconds (default: {flag_reseal_min_period}).