add test and fix for canvas::isClipEmpty

BUG=skia:

Change-Id: I4e57e0da7111e861fbae1b88574bc1803442243c
Reviewed-on: https://skia-review.googlesource.com/10046
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Commit-Queue: Derek Sollenberger <djsollen@google.com>

2 files changed, 6 insertions, 3 deletions

diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index 45acc535d7..030180475d 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -1610,9 +1610,14 @@ void SkCanvas::temporary_internal_getRgnClip(SkRegion* rgn) {
 ///////////////////////////////////////////////////////////////////////////////
 
 bool SkCanvas::isClipEmpty() const {
+    return fMCRec->fRasterClip.isEmpty();
+
+    // TODO: should we only use the conservative answer in a recording canvas?
+#if 0
     SkBaseDevice* dev = this->getTopDevice();
     // if no device we return true
     return !dev || dev->onGetClipType() == SkBaseDevice::kEmpty_ClipType;
+#endif
 }
 
 bool SkCanvas::isClipRect() const {
diff --git a/src/core/SkRasterClip.cpp b/src/core/SkRasterClip.cpp
index 090297d8ba..a08119a34d 100644
--- a/src/core/SkRasterClip.cpp
+++ b/src/core/SkRasterClip.cpp
@@ -108,10 +108,8 @@ void SkConservativeClip::op(const SkRegion& rgn, SkRegion::Op op) {
 
 void SkConservativeClip::op(const SkIRect& devRect, SkRegion::Op op) {
     if (SkRegion::kIntersect_Op == op) {
-        if (devRect.isEmpty()) {
+        if (!fBounds.intersect(devRect)) {
             fBounds.setEmpty();
-        } else {
-            (void)fBounds.intersect(devRect);
         }
         return;
     }