heal: Preserve deployment ID from reference format.json (#7126)

Deployment ID is not copied into new formats after healing format. Although,
this is not critical since a new deployment ID will be generated and set in the
next cluster restart, it is still much better if we don't change the deployment
id of a cluster for a better tracking.

cmd/format-xl.go

@@ -896,6 +896,7 @@ func newHealFormatSets(refFormat *formatXLV3, setCount, disksPerSet int, formats
 			if errs[i*disksPerSet+j] == errUnformattedDisk || errs[i*disksPerSet+j] == nil {
 				newFormats[i][j] = &formatXLV3{}
 				newFormats[i][j].Version = refFormat.Version
+				newFormats[i][j].ID = refFormat.ID
 				newFormats[i][j].Format = refFormat.Format
 				newFormats[i][j].XL.Version = refFormat.XL.Version
 				newFormats[i][j].XL.DistributionAlgo = refFormat.XL.DistributionAlgo

cmd/format-xl_test.go

@@ -556,4 +556,13 @@ func TestNewFormatSets(t *testing.T) {
 	if newFormats == nil {
 		t.Fatal("Unexpected failure")
 	}
+
+	// Check if deployment IDs are preserved.
+	for i := range newFormats {
+		for j := range newFormats[i] {
+			if newFormats[i][j].ID != quorumFormat.ID {
+				t.Fatal("Deployment id in the new format is lost")
+			}
+		}
+	}
 }