Handle negative rotation case in CPDF_Page::GetDisplayMatrix()
Catch the default case in a switch-statement and just return a
CFX_Matrix of all zeroes.
Change-Id: I03b98b23a02aa6138f28c5ac79c9cbcf8fb97cf6
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/132230
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fpdfapi/page/cpdf_page.cpp b/core/fpdfapi/page/cpdf_page.cpp
index 795fd19..556fed7 100644
--- a/core/fpdfapi/page/cpdf_page.cpp
+++ b/core/fpdfapi/page/cpdf_page.cpp
@@ -128,20 +128,19 @@
return CFX_Matrix();
}
- float x0 = 0;
- float y0 = 0;
- float x1 = 0;
- float y1 = 0;
- float x2 = 0;
- float y2 = 0;
- rotation %= 4;
+ float x0;
+ float y0;
+ float x1;
+ float y1;
+ float x2;
+ float y2;
// This code implicitly inverts the y-axis to account for page coordinates
// pointing up and bitmap coordinates pointing down. (x0, y0) is the base
// point, (x1, y1) is that point translated on y and (x2, y2) is the point
// translated on x. On rotation = 0, y0 is rect.bottom and the translation
// to get y1 is performed as negative. This results in the desired
// transformation.
- switch (rotation) {
+ switch (rotation % 4) {
case 0:
x0 = rect.left;
y0 = rect.bottom;
@@ -174,6 +173,11 @@
x2 = rect.right;
y2 = rect.top;
break;
+ default:
+ CHECK_LT(rotation, 0);
+ // Handing this with `rotation += 4` breaks public API compatibility. So
+ // just return early here without doing all the matrix calculations below.
+ return CFX_Matrix(0, 0, 0, 0, 0, 0);
}
CFX_Matrix matrix((x2 - x0) / page_size_.width, (y2 - y0) / page_size_.width,
(x1 - x0) / page_size_.height,
