Fix behavior of FPDF_RenderPageBitmapWithMatrix

This functional part of this CL is mostly a revert of
"Change behaviour of FPDF_RenderPageBitmapWithMatrix"
24b0733a72bbc4013bff8628f198b0aea807aa06

Besides the revert, the parameters passed to
pPage->GetDisplayMatrix() are changed to fix a bug with the previous
implementation: the page was scaled to fit inside the clipping_rect,
instead of clipped.

Bug: pdfium:849
Change-Id: I95d0a303a979c998026a3bd6963c8684a1209f03
Reviewed-on: https://pdfium-review.googlesource.com/22931
Reviewed-by: Nicolás Peña Moreno <npm@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>

1 files changed, 10 insertions, 7 deletions

diff --git a/fpdfsdk/fpdfview.cpp b/fpdfsdk/fpdfview.cpp
index cec44a48f9..97fc02a234 100644
--- a/fpdfsdk/fpdfview.cpp
+++ b/fpdfsdk/fpdfview.cpp
@@ -1034,13 +1034,16 @@ FPDF_RenderPageBitmapWithMatrix(FPDF_BITMAP bitmap,
   if (clipping)
     clipping_rect = CFXFloatRectFromFSRECTF(*clipping);
   FX_RECT clip_rect = clipping_rect.ToFxRect();
-  RenderPageImpl(
-      pContext, pPage,
-      pPage->GetDisplayMatrixWithTransformation(
-          clip_rect.left, clip_rect.top, clip_rect.Width(), clip_rect.Height(),
-          CFX_Matrix(matrix->a, matrix->b, matrix->c, matrix->d, matrix->e,
-                     matrix->f)),
-      clip_rect, flags, true, nullptr);
+
+  CFX_Matrix transform_matrix = pPage->GetDisplayMatrix(
+      0, 0, pPage->GetPageWidth(), pPage->GetPageHeight(), 0);
+
+  if (matrix) {
+    transform_matrix.Concat(CFX_Matrix(matrix->a, matrix->b, matrix->c,
+                                       matrix->d, matrix->e, matrix->f));
+  }
+  RenderPageImpl(pContext, pPage, transform_matrix, clip_rect, flags, true,
+                 nullptr);
 
   pPage->SetRenderContext(nullptr);
 }