check for irect with overflow width/height

Bug:798066
Change-Id: Iac324ac5a32fae241a528751c84279ce60ac4baf
Reviewed-on: https://skia-review.googlesource.com/90544
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Reed <reed@google.com>
This commit is contained in:
Mike Reed 2018-01-03 15:35:33 -05:00 committed by Skia Commit-Bot
parent 3a8a277d93
commit 9fc53624a0
5 changed files with 64 additions and 11 deletions

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@ -10,6 +10,7 @@
#include "SkPoint.h"
#include "SkSize.h"
#include "../private/SkPedanticMath.h"
#include "../private/SkTFitsIn.h"
struct SkRect;
@ -117,56 +118,56 @@ struct SK_API SkIRect {
@return fLeft
*/
int left() const { return fLeft; }
int32_t left() const { return fLeft; }
/** Returns top edge of SkIRect, if sorted. Call isEmpty() to see if SkIRect may be invalid,
and sort() to reverse fTop and fBottom if needed.
@return fTop
*/
int top() const { return fTop; }
int32_t top() const { return fTop; }
/** Returns right edge of SkIRect, if sorted.
Call sort() to reverse fLeft and fRight if needed.
@return fRight
*/
int right() const { return fRight; }
int32_t right() const { return fRight; }
/** Returns bottom edge of SkIRect, if sorted. Call isEmpty() to see if SkIRect may be invalid,
and sort() to reverse fTop and fBottom if needed.
@return fBottom
*/
int bottom() const { return fBottom; }
int32_t bottom() const { return fBottom; }
/** Returns left edge of SkIRect, if sorted. Call isEmpty() to see if SkIRect may be invalid,
and sort() to reverse fLeft and fRight if needed.
@return fLeft
*/
int x() const { return fLeft; }
int32_t x() const { return fLeft; }
/** Returns top edge of SkIRect, if sorted. Call isEmpty() to see if SkIRect may be invalid,
and sort() to reverse fTop and fBottom if needed.
@return fTop
*/
int y() const { return fTop; }
int32_t y() const { return fTop; }
/** Returns span on the x-axis. This does not check if SkIRect is sorted, or if
result fits in 32-bit signed integer; result may be negative.
@return fRight minus fLeft
*/
int width() const { return fRight - fLeft; }
int32_t width() const { return SkSub32(fRight, fLeft); }
/** Returns span on the y-axis. This does not check if SkIRect is sorted, or if
result fits in 32-bit signed integer; result may be negative.
@return fBottom minus fTop
*/
int height() const { return fBottom - fTop; }
int32_t height() const { return SkSub32(fBottom, fTop); }
/** Returns spans on the x-axis and y-axis. This does not check if SkIRect is sorted,
or if result fits in 32-bit signed integer; result may be negative.
@ -182,7 +183,7 @@ struct SK_API SkIRect {
@return midpoint in x
*/
int centerX() const { return (fRight + fLeft) >> 1; }
int32_t centerX() const { return (fRight + fLeft) >> 1; }
/** Returns average of top edge and bottom edge. Result does not change if SkRect
is sorted. Result may be incorrect if SkRect is far from the origin.
@ -191,7 +192,7 @@ struct SK_API SkIRect {
@return midpoint in y
*/
int centerY() const { return (fBottom + fTop) >> 1; }
int32_t centerY() const { return (fBottom + fTop) >> 1; }
/** Returns true if fLeft is equal to or greater than fRight, or if fTop is equal
to or greater than fBottom. Call sort() to reverse rectangles with negative

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@ -0,0 +1,17 @@
/*
* Copyright 2018 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkPedanticMath_DEFINED
#define SkPedanticMath_DEFINED
// To avoid UBSAN complaints about 2's compliment overflows
//
static inline int32_t SkSub32(int32_t a, int32_t b) {
return (int32_t)((uint32_t)a - (uint32_t)b);
}
#endif

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@ -9,6 +9,7 @@
#include "SkAtomics.h"
#include "SkBlitter.h"
#include "SkColorData.h"
#include "SkRectPriv.h"
#include "SkPath.h"
#include "SkScan.h"
#include "SkUtils.h"
@ -703,7 +704,7 @@ bool SkAAClip::setEmpty() {
}
bool SkAAClip::setRect(const SkIRect& bounds) {
if (bounds.isEmpty()) {
if (!SkRectPriv::PositiveDimensions(bounds)) {
return this->setEmpty();
}

24
src/core/SkRectPriv.h Normal file
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@ -0,0 +1,24 @@
/*
* Copyright 2018 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkRectPriv_DEFINED
#define SkRectPriv_DEFINED
#include "SkRect.h"
class SkRectPriv {
public:
// Returns true iff width and height are positive. Catches inverted, empty, and overflowing
// (way too big) rects. This is used by clients that want a non-empty rect that they can also
// actually use its computed width/height.
//
static bool PositiveDimensions(const SkIRect& r) {
return r.width() > 0 && r.height() > 0;
}
};
#endif

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@ -409,6 +409,15 @@ static void test_crbug_422693(skiatest::Reporter* reporter) {
rc.op(path, SkMatrix::I(), rc.getBounds(), SkRegion::kIntersect_Op, true);
}
static void test_huge(skiatest::Reporter* reporter) {
SkAAClip clip;
int big = 0x70000000;
SkIRect r = { -big, -big, big, big };
SkASSERT(r.width() < 0 && r.height() < 0);
clip.setRect(r);
}
DEF_TEST(AAClip, reporter) {
test_empty(reporter);
test_path_bounds(reporter);
@ -419,4 +428,5 @@ DEF_TEST(AAClip, reporter) {
test_nearly_integral(reporter);
test_really_a_rect(reporter);
test_crbug_422693(reporter);
test_huge(reporter);
}