Add two NULL argument FPDFDest_* test cases

Change-Id: I4b811bb28f9af5fd4a907a9a9eb29b05a8dc4b6a
Reviewed-on: https://pdfium-review.googlesource.com/c/43731
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>

fpdfsdk/fpdf_doc.cpp

diff --git a/fpdfsdk/fpdf_doc.cpp b/fpdfsdk/fpdf_doc.cpp
index b8f50c7..614462f 100644
--- a/fpdfsdk/fpdf_doc.cpp
+++ b/fpdfsdk/fpdf_doc.cpp
@@ -207,13 +207,13 @@
 
 FPDF_EXPORT int FPDF_CALLCONV FPDFDest_GetDestPageIndex(FPDF_DOCUMENT document,
                                                         FPDF_DEST dest) {
-  if (!dest)
-    return -1;
-
   CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
   if (!pDoc)
     return -1;
 
+  if (!dest)
+    return -1;
+
   CPDF_Dest destination(CPDFArrayFromFPDFDest(dest));
   return destination.GetDestPageIndex(pDoc);
 }

fpdfsdk/fpdf_doc_embeddertest.cpp

diff --git a/fpdfsdk/fpdf_doc_embeddertest.cpp b/fpdfsdk/fpdf_doc_embeddertest.cpp
index d90cc37..3d582bc 100644
--- a/fpdfsdk/fpdf_doc_embeddertest.cpp
+++ b/fpdfsdk/fpdf_doc_embeddertest.cpp
@@ -42,7 +42,8 @@
 TEST_F(FPDFDocEmbeddertest, DestGetPageIndex) {
   EXPECT_TRUE(OpenDocument("named_dests.pdf"));
 
-  // NULL FPDF_DEST case.
+  // NULL argument cases.
+  EXPECT_EQ(-1, FPDFDest_GetDestPageIndex(nullptr, nullptr));
   EXPECT_EQ(-1, FPDFDest_GetDestPageIndex(document(), nullptr));
 
   // Page number directly in item from Dests NameTree.
@@ -128,18 +129,21 @@
 TEST_F(FPDFDocEmbeddertest, DestGetLocationInPage) {
   EXPECT_TRUE(OpenDocument("named_dests.pdf"));
 
-  // NULL FPDF_DEST case.
-  EXPECT_EQ(-1, FPDFDest_GetDestPageIndex(document(), nullptr));
-
   FPDF_DEST dest = FPDF_GetNamedDestByName(document(), "First");
   EXPECT_TRUE(dest);
 
-  FPDF_BOOL hasX;
-  FPDF_BOOL hasY;
-  FPDF_BOOL hasZoom;
-  FS_FLOAT x;
-  FS_FLOAT y;
-  FS_FLOAT zoom;
+  FPDF_BOOL hasX = 0;
+  FPDF_BOOL hasY = 0;
+  FPDF_BOOL hasZoom = 0;
+  FS_FLOAT x = -1.0f;
+  FS_FLOAT y = -1.0f;
+  FS_FLOAT zoom = -1.0f;
+
+  // NULL argument case
+  EXPECT_FALSE(FPDFDest_GetLocationInPage(nullptr, &hasX, &hasY, &hasZoom, &x,
+                                          &y, &zoom));
+
+  // Actual argument case.
   EXPECT_TRUE(
       FPDFDest_GetLocationInPage(dest, &hasX, &hasY, &hasZoom, &x, &y, &zoom));
   EXPECT_TRUE(hasX);