Merge to XFA:Fix heap use after free in CPDFSDK_Annot::GetPDFAnnot.

fpdfsdk/src/fpdfformfill_embeddertest.cpp

Index: fpdfsdk/src/fpdfformfill_embeddertest.cpp
diff --git a/fpdfsdk/src/fpdfformfill_embeddertest.cpp b/fpdfsdk/src/fpdfformfill_embeddertest.cpp
index 6baad115313eaf805d839cf94481e97dd951d43f..56710b9f8369e9bbbcefc349e51e63cfb436d184 100644
--- a/fpdfsdk/src/fpdfformfill_embeddertest.cpp
+++ b/fpdfsdk/src/fpdfformfill_embeddertest.cpp
@@ -40,6 +40,18 @@ TEST_F(FPDFFormFillEmbeddertest, BUG_487928) {
   UnloadPage(page);
 }
 
+TEST_F(FPDFFormFillEmbeddertest, BUG_507316) {
+  EmbedderTestTimerHandlingDelegate delegate;
+  SetDelegate(&delegate);
+
+  EXPECT_TRUE(OpenDocument("testing/resources/bug_507316.pdf"));
+  FPDF_PAGE page = LoadAndCachePage(2);
+  EXPECT_NE(nullptr, page);
+  DoOpenActions();
+  delegate.AdvanceTime(4000);
+  UnloadPage(page);
+}
+
 TEST_F(FPDFFormFillEmbeddertest, BUG_514690) {
   EXPECT_TRUE(OpenDocument("testing/resources/hello_world.pdf"));
   FPDF_PAGE page = LoadPage(0);