Fix rendering artifacts in pull-saveLayers-forward mode

src/core/SkPicturePlayback.cpp

Index: src/core/SkPicturePlayback.cpp
===================================================================
--- src/core/SkPicturePlayback.cpp	(revision 14632)
+++ src/core/SkPicturePlayback.cpp	(working copy)
@@ -896,33 +896,44 @@
             if (NULL != temp) {
                 SkASSERT(NULL != temp->fBM);
                 SkASSERT(NULL != temp->fPaint);
+                canvas.save();
+                canvas.setMatrix(initialMatrix);
                 canvas.drawBitmap(*temp->fBM, temp->fPos.fX, temp->fPos.fY, temp->fPaint);
+                canvas.restore();
 
                 if (it.isValid()) {
                     // This save is needed since the BBH will automatically issue
                     // a restore to balanced the saveLayer we're skipping
                     canvas.save();
-                    // Note: This skipping only works if the client only issues
-                    // well behaved saveLayer calls (i.e., doesn't use 
-                    // kMatrix_SaveFlag or kClip_SaveFlag in isolation)
-
                     // At this point we know that the PictureStateTree was aiming
                     // for some draw op within temp's saveLayer (although potentially
                     // in a separate saveLayer nested inside it).
                     // We need to skip all the operations inside temp's range
                     // along with all the associated state changes but update 
                     // the state tree to the first operation outside temp's range.
-                    SkASSERT(it.peekDraw() >= temp->fStart && it.peekDraw() <= temp->fStop);
 
-                    while (kDrawComplete != it.peekDraw() && it.peekDraw() <= temp->fStop) {
-                        it.skipDraw();
-                    }
+                    uint32_t skipTo;
+                    do {
+                        skipTo = it.nextDraw();
+                        if (kDrawComplete == skipTo) {
+                            break;
+                        }
 
-                    if (kDrawComplete == it.peekDraw()) {
+                        if (skipTo <= temp->fStop) {
+                            reader.setOffset(skipTo);
+                            uint32_t size;
+                            DrawType op = read_op_and_size(&reader, &size);
+                            // Convert nested saveLayers into saves

[bsalomon, 2014/05/08 13:50:46]

?

[robertphillips, 2014/05/08 18:45:41]

Done - expanded comment.

+                            if (SAVE_LAYER == op) {
+                                canvas.save();
+                            }
+                        }
+                    } while (skipTo <= temp->fStop);
+
+                    if (kDrawComplete == skipTo) {
                         break;
                     }
 
-                    uint32_t skipTo = it.nextDraw();
                     reader.setOffset(skipTo);
                 } else {
                     reader.setOffset(temp->fStop);