stamping: Fix OCG reuse

pdfcpu · Jul 29, 2021 · 16f43aa · 16f43aa
1 parent c3eb4c0
commit 16f43aa
Showing 1 changed file with 6 additions and 5 deletions.
diff --git a/pkg/pdfcpu/stamp.go b/pkg/pdfcpu/stamp.go
@@ -1247,12 +1247,13 @@ func (ctx *Context) prepareOCPropertiesInRoot(onTop bool) (*IndirectRef, error)
 			if err != nil {
 				return nil, errCorruptOCGs
 			}
-
-			ir, ok := a[0].(IndirectRef)
-			if !ok {
-				return nil, errCorruptOCGs
+			if len(a) > 0 {
+				ir, ok := a[0].(IndirectRef)
+				if !ok {
+					return nil, errCorruptOCGs
+				}
+				return &ir, nil
 			}
-			return &ir, nil
 		}
 	}