Catch invalid images in get_images_from_skps

tools/get_images_from_skps.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCodec.h"
 #include "SkCommandLineFlags.h"
 #include "SkData.h"
 #include "SkMD5.h"
 #include "SkOSFile.h"
 #include "SkPicture.h"
 #include "SkPixelSerializer.h"
 #include "SkStream.h"
 #include "SkTHash.h"
 
 DEFINE_string2(skps, s, "skps", "A path to a directory of skps.");
 DEFINE_string2(out, o, "img-out", "A path to an output directory.");
+DEFINE_bool(test, false, "Indicates if we want to test that the images decode successfully.");
 
 static int gKnown;
 static int gUnknown;
 static const char* gOutputDir;
 
 static SkTHashSet<SkMD5::Digest> gSeen;
 
 struct Sniffer : public SkPixelSerializer {
 
     void sniff(const void* ptr, size_t len) {
@@ skipping 19 matching lines @@
             case SkEncodedFormat::kGIF_SkEncodedFormat:  ext =  "gif"; break;
             case SkEncodedFormat::kICO_SkEncodedFormat:  ext =  "ico"; break;
             case SkEncodedFormat::kJPEG_SkEncodedFormat: ext =  "jpg"; break;
             case SkEncodedFormat::kPNG_SkEncodedFormat:  ext =  "png"; break;
             case SkEncodedFormat::kDNG_SkEncodedFormat:  ext =  "dng"; break;
             case SkEncodedFormat::kWBMP_SkEncodedFormat: ext = "wbmp"; break;
             case SkEncodedFormat::kWEBP_SkEncodedFormat: ext = "webp"; break;
             default: gUnknown++; return;
         }
 
+        if (FLAGS_test) {
+            SkBitmap bitmap;
+            SkImageInfo info = codec->getInfo().makeColorType(kN32_SkColorType);
+            bitmap.allocPixels(info);
+            if (SkCodec::kSuccess != codec->getPixels(info, bitmap.getPixels(), bitmap.rowBytes()))
+            {
+                gUnknown++;
+                return;
+            }
+        }
+
         SkString path;
         path.appendf("%s/%d.%s", gOutputDir, gKnown++, ext.c_str());
 
         SkFILEWStream file(path.c_str());
         file.write(ptr, len);
 
         SkDebugf("%s\n", path.c_str());
     }
 
     bool onUseEncodedData(const void* ptr, size_t len) override {
@@ skipping 24 matching lines @@
         sk_sp<SkPicture> picture(SkPicture::MakeFromStream(stream));
 
         SkDynamicMemoryWStream scratch;
         Sniffer sniff;
         picture->serialize(&scratch, &sniff);
     }
     SkDebugf("%d known, %d unknown\n", gKnown, gUnknown);
 
     return 0;
 }