From 6845219e943c95d7f00ecd18035feac15b0921bf Mon Sep 17 00:00:00 2001
From: Alexander Lazarenko <kerblif@unprism.ru>
Date: Thu, 30 Oct 2025 02:10:01 +0300
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---
 api.go | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/api.go b/api.go
index 619bd26..0c59031 100644
--- a/api.go
+++ b/api.go
@@ -487,19 +487,29 @@ func (ag *Agate) RegisterLocalSnapshot(ctx context.Context, snapshotID, parentID
 	}
 
 	// 2. Add the file to the blob store
-	localFile, err := os.Open(localPath)
-	if err != nil {
-		return fmt.Errorf("failed to open local snapshot file: %w", err)
-	}
-	defer func() {
-		if err := localFile.Close(); err != nil {
-			ag.options.Logger.Printf("ERROR: failed to close local file: %v", err)
+	// Check if blob already exists. If so, we assume it's the correct one and skip overwriting.
+	// This is to prevent issues when registering a file that is already in the blob store.
+	_, err = ag.options.BlobStore.GetBlobPath(ctx, snapshotID)
+	if err == nil {
+		ag.options.Logger.Printf("blob for snapshot %s already exists, skipping storing it", snapshotID)
+	} else if errors.Is(err, models.ErrNotFound) {
+		// Blob does not exist, so we store it.
+		localFile, err := os.Open(localPath)
+		if err != nil {
+			return fmt.Errorf("failed to open local snapshot file: %w", err)
 		}
-	}()
+		defer func() {
+			if err := localFile.Close(); err != nil {
+				ag.options.Logger.Printf("ERROR: failed to close local file: %v", err)
+			}
+		}()
 
-	_, err = ag.options.BlobStore.StoreBlob(ctx, snapshotID, localFile)
-	if err != nil {
-		return fmt.Errorf("failed to store blob from local file: %w", err)
+		if _, err = ag.options.BlobStore.StoreBlob(ctx, snapshotID, localFile); err != nil {
+			return fmt.Errorf("failed to store blob from local file: %w", err)
+		}
+	} else {
+		// Another error occurred when checking for the blob.
+		return fmt.Errorf("failed to check for existing blob: %w", err)
 	}
 
 	// 3. Create and save snapshot metadata