Cover CPDFXFA_Context::SavePackage() from embeddertest

Change-Id: Ifa38af2b765eb6bec872bd76e4071c294f31f005
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/65331
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

fpdfsdk/fpdf_save_embeddertest.cpp

diff --git a/fpdfsdk/fpdf_save_embeddertest.cpp b/fpdfsdk/fpdf_save_embeddertest.cpp
index e9e94ca..614b4f4 100644
--- a/fpdfsdk/fpdf_save_embeddertest.cpp
+++ b/fpdfsdk/fpdf_save_embeddertest.cpp
@@ -92,6 +92,17 @@
   CloseSavedDocument();
 }
 
+#ifdef PDF_ENABLE_XFA
+TEST_F(FPDFSaveEmbedderTest, SaveXFADoc) {
+  ASSERT_TRUE(OpenDocument("simple_xfa.pdf"));
+  EXPECT_TRUE(FPDF_SaveAsCopy(document(), this, 0));
+  EXPECT_THAT(GetString(), testing::StartsWith("%PDF-1.7\r\n"));
+  ASSERT_TRUE(OpenSavedDocument());
+  // TODO(tsepez): check for XFA forms in document
+  CloseSavedDocument();
+}
+#endif  // PDF_ENABLE_XFA
+
 TEST_F(FPDFSaveEmbedderTest, BUG_342) {
   EXPECT_TRUE(OpenDocument("hello_world.pdf"));
   EXPECT_TRUE(FPDF_SaveAsCopy(document(), this, 0));