Add more defensive checks around nil derefs

stellar · Apr 21, 2022 · 4096c08 · 4096c08
1 parent 17a88bd
commit 4096c08
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Showing 2 changed files with 14 additions and 5 deletions.
diff --git a/services/horizon/internal/integration/transaction_preconditions_test.go b/services/horizon/internal/integration/transaction_preconditions_test.go
@@ -395,6 +395,10 @@ func TestTransactionWithoutPreconditions(t *testing.T) {
 	tt.NoError(err)
 	b64 := base64.StdEncoding.EncodeToString(txBytes.Bytes())
 
-	_, err = itest.Client().SubmitTransactionXDR(b64)
+	txResp, err := itest.Client().SubmitTransactionXDR(b64)
 	tt.NoError(err)
+
+	txResp2, err := itest.Client().TransactionDetail(txResp.Hash)
+	tt.NoError(err)
+	tt.Nil(txResp2.Preconditions)
 }
diff --git a/services/horizon/internal/resourceadapter/transaction.go b/services/horizon/internal/resourceadapter/transaction.go
@@ -55,9 +55,9 @@ func PopulateTransaction(
 	}
 	dest.Signatures = row.Signatures
 
-	if row.HasPreconditions() {
-		dest.Preconditions = &protocol.TransactionPreconditions{}
-	}
+	// Prepare it unconditionally to be defensive against accidental nil
+	// dereferences further down.
+	dest.Preconditions = &protocol.TransactionPreconditions{}
 
 	if !row.TimeBounds.Null {
 		// Action needed in release: horizon-v3.0.0: remove ValidBefore and ValidAfter
@@ -95,7 +95,7 @@ func PopulateTransaction(
 		dest.Preconditions.MinAccountSequenceLedgerGap = uint32(row.MinAccountSequenceLedgerGap.Int64)
 	}
 
-	if row.ExtraSigners != nil {
+	if len(row.ExtraSigners) > 0 {
 		dest.Preconditions.ExtraSigners = row.ExtraSigners
 	}
 
@@ -136,6 +136,11 @@ func PopulateTransaction(
 	dest.Links.Succeeds = lb.Linkf("/transactions?order=desc&cursor=%s", dest.PT)
 	dest.Links.Precedes = lb.Linkf("/transactions?order=asc&cursor=%s", dest.PT)
 
+	// If we didn't need the structure, drop it.
+	if !row.HasPreconditions() {
+		dest.Preconditions = nil
+	}
+
 	return nil
 }