feat(加强兼容): 支持多文档

ofdgo_sign_verify.go

@@ -299,7 +299,7 @@ func (r *Reader) VerifyDocumentSignatures(index int, opts ...SignatureVerifyOpti
 	}
 	body := r.OFD.DocBody[index]
 	options.DocIndex, options.DocRoot = index, r.signatureCoveragePath(body.DocRoot)
-	if index == 0 && r.doc != nil && r.doc.Signatures == "" {
+	if index == r.documentIndex && r.doc != nil && r.doc.Signatures == "" {
 		return nil, nil
 	}
 	data, err := r.readFile(body.DocRoot)
@@ -316,7 +316,10 @@ func (r *Reader) VerifyDocumentSignatures(index int, opts ...SignatureVerifyOpti
 	if doc.Signatures == "" {
 		return nil, nil
 	}
-	view := *r
+	view := &Reader{Zip: r.Zip, files: r.files, encryption: r.encryption, documentIndex: index}
+	if err := view.initRoot(); err != nil {
+		return nil, err
+	}
 	view.doc, view.RootDir = &doc, path.Dir(body.DocRoot)
 	sigListPath := view.ResPath(doc.Signatures)
 	data, err = view.readFile(sigListPath)