Fix rotationschromium/3086chromium/3085

Normalize rotations read from PDF documents. Make FPDFPage_GetRotation
always return a value 0 to 3 as specified in fpdf_edit.h instead of
returning the page rotation / 90 (page rotation may be negative for some
PDFs).

BUG=chromium:713197

Change-Id: Ie477803f7d298b777a3ace89b21cfda8b7f6808b
Reviewed-on: https://pdfium-review.googlesource.com/4532
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

3 files changed, 12 insertions, 27 deletions

diff --git a/fpdfsdk/fpdfedit_embeddertest.cpp b/fpdfsdk/fpdfedit_embeddertest.cpp
index 952564db49..d62f5ca85c 100644
--- a/fpdfsdk/fpdfedit_embeddertest.cpp
+++ b/fpdfsdk/fpdfedit_embeddertest.cpp
@@ -694,3 +694,13 @@ TEST_F(FPDFEditEmbeddertest, LoadCIDType2Font) {
   ASSERT_TRUE(widths_array);
   CheckCompositeFontWidths(widths_array, typed_font);
 }
+
+TEST_F(FPDFEditEmbeddertest, NormalizeNegativeRotation) {
+  // Load document with a -90 degree rotation
+  EXPECT_TRUE(OpenDocument("bug_713197.pdf"));
+  FPDF_PAGE page = LoadPage(0);
+  EXPECT_NE(nullptr, page);
+
+  EXPECT_EQ(3, FPDFPage_GetRotation(page));
+  UnloadPage(page);
+}
diff --git a/fpdfsdk/fpdfeditpage.cpp b/fpdfsdk/fpdfeditpage.cpp
index 511b7f5b4b..739723f6ee 100644
--- a/fpdfsdk/fpdfeditpage.cpp
+++ b/fpdfsdk/fpdfeditpage.cpp
@@ -133,20 +133,7 @@ DLLEXPORT int STDCALL FPDFPage_GetRotation(FPDF_PAGE page) {
   CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
   if (!IsPageObject(pPage))
     return -1;
-
-  CPDF_Dictionary* pDict = pPage->m_pFormDict;
-  while (pDict) {
-    if (pDict->KeyExist("Rotate")) {
-      CPDF_Object* pRotateObj = pDict->GetObjectFor("Rotate")->GetDirect();
-      return pRotateObj ? pRotateObj->GetInteger() / 90 : 0;
-    }
-    if (!pDict->KeyExist("Parent"))
-      break;
-
-    pDict = ToDictionary(pDict->GetObjectFor("Parent")->GetDirect());
-  }
-
-  return 0;
+  return pPage->GetPageRotation();
 }
 
 DLLEXPORT void STDCALL FPDFPage_InsertObject(FPDF_PAGE page,
diff --git a/fpdfsdk/fpdfview.cpp b/fpdfsdk/fpdfview.cpp
index 4fea392228..c928ebe445 100644
--- a/fpdfsdk/fpdfview.cpp
+++ b/fpdfsdk/fpdfview.cpp
@@ -740,19 +740,7 @@ FX_RECT GetMaskDimensionsAndOffsets(CPDF_Page* pPage,
                   static_cast<int>(mask_box.bottom * scale_y);
 
   // Get page rotation
-  int page_rotation = 0;
-  CPDF_Dictionary* pDict = pPage->m_pFormDict;
-  while (pDict) {
-    if (pDict->KeyExist("Rotate")) {
-      CPDF_Object* pRotateObj = pDict->GetObjectFor("Rotate")->GetDirect();
-      page_rotation = pRotateObj ? pRotateObj->GetInteger() / 90 : 0;
-      break;
-    }
-    if (!pDict->KeyExist("Parent"))
-      break;
-
-    pDict = ToDictionary(pDict->GetObjectFor("Parent")->GetDirect());
-  }
+  int page_rotation = pPage->GetPageRotation();
 
   // Compute offsets
   int offset_x = 0;