From b862e271a12b07907e9d804d78739d60222a1f4d Mon Sep 17 00:00:00 2001
From: Alexander Bezobchuk <alexanderbez@users.noreply.github.com>
Date: Tue, 3 Dec 2019 04:24:12 -0500
Subject: [PATCH] Allow node to restart after halt config trigger (#5352)

* Allow node to restart after halt config trigger

* Update godoc

* Update documentation on halt config
---
 CHANGELOG.md            |  2 ++
 baseapp/abci.go         | 36 ++++++++++++++++++------------------
 server/config/config.go |  6 ++----
 server/config/toml.go   |  6 ++----
 4 files changed, 24 insertions(+), 26 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d5ed05db7416..c7783efc23de 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -196,6 +196,8 @@ to detail this new feature and how state transitions occur.
 * (keys) Fix ledger custom coin type support bug
 * (x/gov) [\#5107](https://github.com/cosmos/cosmos-sdk/pull/5107) Sum validator operator's all voting power when tally votes
 * (rest) [\#5212](https://github.com/cosmos/cosmos-sdk/issues/5212) Fix pagination in the `/gov/proposals` handler.
+* (baseapp) [\#5350](https://github.com/cosmos/cosmos-sdk/issues/5350) Allow a node to restart successfully after a `halt-height` or `halt-time`
+  has been triggered.
 
 ## [v0.37.4] - 2019-11-04
 
diff --git a/baseapp/abci.go b/baseapp/abci.go
index ef8c71d4222a..e93b7c56c2c9 100644
--- a/baseapp/abci.go
+++ b/baseapp/abci.go
@@ -215,24 +215,6 @@ func (app *BaseApp) DeliverTx(req abci.RequestDeliverTx) (res abci.ResponseDeliv
 func (app *BaseApp) Commit() (res abci.ResponseCommit) {
 	header := app.deliverState.ctx.BlockHeader()
 
-	var halt bool
-
-	switch {
-	case app.haltHeight > 0 && uint64(header.Height) >= app.haltHeight:
-		halt = true
-
-	case app.haltTime > 0 && header.Time.Unix() >= int64(app.haltTime):
-		halt = true
-	}
-
-	if halt {
-		app.halt()
-
-		// Note: State is not actually committed when halted. Logs from Tendermint
-		// can be ignored.
-		return abci.ResponseCommit{}
-	}
-
 	// Write the DeliverTx state which is cache-wrapped and commit the MultiStore.
 	// The write to the DeliverTx state writes all state transitions to the root
 	// MultiStore (app.cms) so when Commit() is called is persists those values.
@@ -249,6 +231,24 @@ func (app *BaseApp) Commit() (res abci.ResponseCommit) {
 	// empty/reset the deliver state
 	app.deliverState = nil
 
+	var halt bool
+
+	switch {
+	case app.haltHeight > 0 && uint64(header.Height) >= app.haltHeight:
+		halt = true
+
+	case app.haltTime > 0 && header.Time.Unix() >= int64(app.haltTime):
+		halt = true
+	}
+
+	if halt {
+		// Halt the binary and allow Tendermint to receive the ResponseCommit
+		// response with the commit ID hash. This will allow the node to successfully
+		// restart and process blocks assuming the halt configuration has been
+		// reset or moved to a more distant value.
+		app.halt()
+	}
+
 	return abci.ResponseCommit{
 		Data: commitID.Hash,
 	}
diff --git a/server/config/config.go b/server/config/config.go
index fc9ead54b466..9752ae85273a 100644
--- a/server/config/config.go
+++ b/server/config/config.go
@@ -22,16 +22,14 @@ type BaseConfig struct {
 	// HaltHeight contains a non-zero block height at which a node will gracefully
 	// halt and shutdown that can be used to assist upgrades and testing.
 	//
-	// Note: State will not be committed on the corresponding height and any logs
-	// indicating such can be safely ignored.
+	// Note: Commitment of state will be attempted on the corresponding block.
 	HaltHeight uint64 `mapstructure:"halt-height"`
 
 	// HaltTime contains a non-zero minimum block time (in Unix seconds) at which
 	// a node will gracefully halt and shutdown that can be used to assist
 	// upgrades and testing.
 	//
-	// Note: State will not be committed on the corresponding height and any logs
-	// indicating such can be safely ignored.
+	// Note: Commitment of state will be attempted on the corresponding block.
 	HaltTime uint64 `mapstructure:"halt-time"`
 
 	// InterBlockCache enables inter-block caching.
diff --git a/server/config/toml.go b/server/config/toml.go
index c0e27c69c809..0463d26a93fb 100644
--- a/server/config/toml.go
+++ b/server/config/toml.go
@@ -21,16 +21,14 @@ minimum-gas-prices = "{{ .BaseConfig.MinGasPrices }}"
 # HaltHeight contains a non-zero block height at which a node will gracefully
 # halt and shutdown that can be used to assist upgrades and testing.
 #
-# Note: State will not be committed on the corresponding height and any logs
-# indicating such can be safely ignored.
+# Note: Commitment of state will be attempted on the corresponding block.
 halt-height = {{ .BaseConfig.HaltHeight }}
 
 # HaltTime contains a non-zero minimum block time (in Unix seconds) at which
 # a node will gracefully halt and shutdown that can be used to assist upgrades
 # and testing.
 #
-# Note: State will not be committed on the corresponding height and any logs
-# indicating such can be safely ignored.
+# Note: Commitment of state will be attempted on the corresponding block.
 halt-time = {{ .BaseConfig.HaltTime }}
 
 # InterBlockCache enables inter-block caching.