Make channel-upgrade execute command fully idempotent

The channel-upgrade execute command is basically idempotent.
However, since proposed upgrades are deleted after the channel
upgrade completes, re-running the command previously failed with
the error: "Error: channel upgrade is not initialized."

This behavior caused instability in tests such as:
https://github.com/datachainlab/cosmos-ethereum-ibc-lcp/blob/v0.2.24/tests/e2e/cases/tm2eth/scripts/test-channel-upgrade#L122

To address this, the command now exits with exit code 0 even when
no proposed upgrades exist. Although some users might forget to
run the channel-upgrade init command, they will be notified through
the newly added log message.

Signed-off-by: Takeshi Arabiki <takeshi.arabiki@datachain.jp>

Author: abicky

core/channel-upgrade.go

@@ -382,9 +382,12 @@ func upgradeChannelStep(ctx context.Context, src, dst *ProvableChain, targetSrcS
 	)}
 
 	// check if both chains have reached the target states or UNINIT states
-	if !firstCall && srcState == UPGRADE_STATE_UNINIT && dstState == UPGRADE_STATE_UNINIT ||
-		srcState != UPGRADE_STATE_UNINIT && dstState != UPGRADE_STATE_UNINIT && srcState == targetSrcState && dstState == targetDstState {
-		logger.InfoContext(ctx, "both chains have reached the target states")
+	if srcState == targetSrcState && dstState == targetDstState {
+		if firstCall && srcState == UPGRADE_STATE_UNINIT && dstState == UPGRADE_STATE_UNINIT {
+			logger.InfoContext(ctx, "both chains have already reached the target states, or the channel upgrade has not been initialized")
+		} else {
+			logger.InfoContext(ctx, "both chains have reached the target states")
+		}
 		out.Last = true
 		return out, nil
 	}
@@ -394,7 +397,7 @@ func upgradeChannelStep(ctx context.Context, src, dst *ProvableChain, targetSrcS
 	dstAction := UPGRADE_ACTION_NONE
 	switch {
 	case srcState == UPGRADE_STATE_UNINIT && dstState == UPGRADE_STATE_UNINIT:
-		return nil, errors.New("channel upgrade is not initialized")
+		return nil, errors.New("channel upgrade has not been initialized; it will never reach the target states")
 	case srcState == UPGRADE_STATE_INIT && dstState == UPGRADE_STATE_UNINIT:
 		if dstChan.Channel.UpgradeSequence >= srcChan.Channel.UpgradeSequence {
 			srcAction = UPGRADE_ACTION_CANCEL

tests/cases/tm2tm/scripts/test-channel-upgrade

@@ -140,3 +140,16 @@ $RLY tx channel-upgrade execute ibc01 --target-src-state FLUSHING --target-dst-s
 sleep 20                              # Both chains exceed upgrade.timeout.timestamp
 $RLY tx channel-upgrade execute ibc01 # ibc0,ibc1 <= chanUpgradeTimeout
 checkResult orig
+
+echo '##### case 10 #####'
+# Both chains have already reached the target states, or the channel upgrade has not been initialized
+$RLY tx channel-upgrade execute ibc01
+checkResult orig
+
+echo '##### case 11 #####'
+# The target states will never be reached
+if $RLY tx channel-upgrade execute ibc01 --target-src-state INIT --target-dst-state FLUSHING; then
+    echo 'channel-upgrade completed with exit code 0, but non-zero code was expected' >&2
+    exit 1
+fi
+checkResult orig