Fixing FPDFPage_TransformAnnots

Came across this error in FPDFPage_TransformAnnots, where SetNewAt()
would fail on a bound assertion when a newly created array calls it.
This CL contains a fix in the function and adds an embedder test for
this.

Bug=pdfium:745

Change-Id: I569f225598d956d270ef8f11ee3225acf48aadc7
Reviewed-on: https://pdfium-review.googlesource.com/6353
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Jane Liu <janeliulwq@google.com>

3 files changed, 26 insertions, 6 deletions

diff --git a/fpdfsdk/fpdfannot_embeddertest.cpp b/fpdfsdk/fpdfannot_embeddertest.cpp
index 1f56d22c28..e1da7cc2cd 100644
--- a/fpdfsdk/fpdfannot_embeddertest.cpp
+++ b/fpdfsdk/fpdfannot_embeddertest.cpp
@@ -153,7 +153,7 @@ TEST_F(FPDFAnnotEmbeddertest, AddFirstTextAnnotation) {
   ASSERT_TRUE(page);
   EXPECT_EQ(0, FPDFPage_GetAnnotCount(page));
 
-  // Add an underline annotation to the page.
+  // Add a text annotation to the page.
   FPDF_ANNOTATION annot;
   ASSERT_TRUE(FPDFPage_CreateAnnot(page, FPDF_ANNOT_TEXT, &annot));
 
diff --git a/fpdfsdk/fpdfedit_embeddertest.cpp b/fpdfsdk/fpdfedit_embeddertest.cpp
index 25377fe6f8..40081e6d75 100644
--- a/fpdfsdk/fpdfedit_embeddertest.cpp
+++ b/fpdfsdk/fpdfedit_embeddertest.cpp
@@ -15,6 +15,7 @@
 #include "core/fxcrt/fx_system.h"
 #include "fpdfsdk/fsdk_define.h"
 #include "public/cpp/fpdf_deleters.h"
+#include "public/fpdf_annot.h"
 #include "public/fpdf_edit.h"
 #include "public/fpdfview.h"
 #include "testing/embedder_test.h"
@@ -838,6 +839,23 @@ TEST_F(FPDFEditEmbeddertest, AddTrueTypeFontText) {
   FPDF_CloseDocument(new_doc);
 }
 
+TEST_F(FPDFEditEmbeddertest, TransformAnnot) {
+  // Open a file with one annotation and load its first page.
+  ASSERT_TRUE(OpenDocument("annotation_highlight_long_content.pdf"));
+  FPDF_PAGE page = FPDF_LoadPage(document(), 0);
+  ASSERT_TRUE(page);
+
+  // Add an underline annotation to the page without specifying its rectangle.
+  FPDF_ANNOTATION annot;
+  ASSERT_TRUE(FPDFPage_CreateAnnot(page, FPDF_ANNOT_UNDERLINE, &annot));
+
+  // FPDFPage_TransformAnnots() should run without errors when modifying
+  // annotation rectangles.
+  FPDFPage_TransformAnnots(page, 1, 2, 3, 4, 5, 6);
+
+  UnloadPage(page);
+}
+
 // TODO(npm): Add tests using Japanese fonts in other OS.
 #if _FXM_PLATFORM_ == _FXM_PLATFORM_LINUX_
 TEST_F(FPDFEditEmbeddertest, AddCIDFontText) {
diff --git a/fpdfsdk/fpdfeditpage.cpp b/fpdfsdk/fpdfeditpage.cpp
index da156cd790..22b2261c6f 100644
--- a/fpdfsdk/fpdfeditpage.cpp
+++ b/fpdfsdk/fpdfeditpage.cpp
@@ -298,13 +298,15 @@ DLLEXPORT void STDCALL FPDFPage_TransformAnnots(FPDF_PAGE page,
     matrix.TransformRect(rect);
 
     CPDF_Array* pRectArray = pAnnot->GetAnnotDict()->GetArrayFor("Rect");
-    if (!pRectArray)
+    if (pRectArray)
+      pRectArray->RemoveAt(0, pRectArray->GetCount());
+    else
       pRectArray = pAnnot->GetAnnotDict()->SetNewFor<CPDF_Array>("Rect");
 
-    pRectArray->SetNewAt<CPDF_Number>(0, rect.left);
-    pRectArray->SetNewAt<CPDF_Number>(1, rect.bottom);
-    pRectArray->SetNewAt<CPDF_Number>(2, rect.right);
-    pRectArray->SetNewAt<CPDF_Number>(3, rect.top);
+    pRectArray->AddNew<CPDF_Number>(rect.left);
+    pRectArray->AddNew<CPDF_Number>(rect.bottom);
+    pRectArray->AddNew<CPDF_Number>(rect.right);
+    pRectArray->AddNew<CPDF_Number>(rect.top);
 
     // TODO(unknown): Transform AP's rectangle
   }