fix: incorrect retention height when commitHeight equals minRetainBlocks (#24526)

CHANGELOG.md

@@ -103,6 +103,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (baseapp) [#24074](https://github.com/cosmos/cosmos-sdk/pull/24074) Use CometBFT's ComputeProtoSizeForTxs in defaultTxSelector.SelectTxForProposal for consistency.
 * (cli) [#24090](https://github.com/cosmos/cosmos-sdk/pull/24090) Prune cmd should disable async pruning.
 * (x/auth) [#19239](https://github.com/cosmos/cosmos-sdk/pull/19239) Sets from flag in multi-sign command to avoid no key name provided error.
+* (baseapp) [#24526](https://github.com/cosmos/cosmos-sdk/pull/24526) Fix incorrect retention height when `commitHeight` equals `minRetainBlocks`.
 
 ## [v0.50.12](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.50.12) - 2025-02-20
 

baseapp/abci.go

@@ -1319,8 +1319,11 @@ func (app *BaseApp) CreateQueryContextWithCheckHeader(height int64, prove, check
 // be a need to vary retention for other nodes, e.g. sentry nodes which do not
 // need historical blocks.
 func (app *BaseApp) GetBlockRetentionHeight(commitHeight int64) int64 {
-	// pruning is disabled if minRetainBlocks is zero
-	if app.minRetainBlocks == 0 {
+	// If minRetainBlocks is zero, pruning is disabled and we return 0
+	// If commitHeight is less than or equal to minRetainBlocks, return 0 since there are not enough
+	// blocks to trigger pruning yet. This ensures we keep all blocks until we have at least minRetainBlocks.
+	retentionBlockWindow := commitHeight - int64(app.minRetainBlocks)
+	if app.minRetainBlocks == 0 || retentionBlockWindow <= 0 {
 		return 0
 	}
 
@@ -1362,8 +1365,7 @@ func (app *BaseApp) GetBlockRetentionHeight(commitHeight int64) int64 {
 		}
 	}
 
-	v := commitHeight - int64(app.minRetainBlocks)
-	retentionHeight = minNonZero(retentionHeight, v)
+	retentionHeight = minNonZero(retentionHeight, retentionBlockWindow)
 
 	if retentionHeight <= 0 {
 		// prune nothing in the case of a non-positive height

baseapp/abci_test.go

@@ -1322,6 +1322,18 @@ func TestABCI_GetBlockRetentionHeight(t *testing.T) {
 			commitHeight: 10000,
 			expected:     0,
 		},
+		"no pruning due to min retain blocks equal to commit height": {
+			bapp:         baseapp.NewBaseApp(name, logger, db, nil, baseapp.SetMinRetainBlocks(499000)),
+			maxAgeBlocks: 362880,
+			commitHeight: 499000,
+			expected:     0,
+		},
+		"no pruning due to min retain blocks greater than commit height": {
+			bapp:         baseapp.NewBaseApp(name, logger, db, nil, baseapp.SetMinRetainBlocks(499001)),
+			maxAgeBlocks: 362880,
+			commitHeight: 499000,
+			expected:     0,
+		},
 		"disable pruning": {
 			bapp: baseapp.NewBaseApp(
 				name, logger, db, nil,