Fix color xform width bug when scaling/subsetting

src/codec/SkJpegCodec.cpp

 /*
  * Copyright 2015 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 "SkMSAN.h"
 #include "SkJpegCodec.h"
@@ skipping 477 matching lines @@
     // we will always decode into fSwizzlerSrcRow before swizzling into the next buffer.
     // We can never swizzle "in place" because the swizzler may perform sampling and/or
     // subsetting.
     // When fColorXformSrcRow is non-null, it means that we need to color xform and that
     // we cannot color xform "in place" (many times we can, but not when the dst is F16).
     // In this case, we will color xform from fColorXformSrc into the dst.
     JSAMPLE* decodeDst = (JSAMPLE*) dst;
     uint32_t* swizzleDst = (uint32_t*) dst;
     size_t decodeDstRowBytes = rowBytes;
     size_t swizzleDstRowBytes = rowBytes;
+    int dstWidth = dstInfo.width();
     if (fSwizzleSrcRow && fColorXformSrcRow) {
         decodeDst = (JSAMPLE*) fSwizzleSrcRow;
         swizzleDst = fColorXformSrcRow;
         decodeDstRowBytes = 0;
         swizzleDstRowBytes = 0;
+        dstWidth = fSwizzler->swizzleWidth();
     } else if (fColorXformSrcRow) {
         decodeDst = (JSAMPLE*) fColorXformSrcRow;
         swizzleDst = fColorXformSrcRow;
         decodeDstRowBytes = 0;
         swizzleDstRowBytes = 0;
     } else if (fSwizzleSrcRow) {
         decodeDst = (JSAMPLE*) fSwizzleSrcRow;
         decodeDstRowBytes = 0;
+        dstWidth = fSwizzler->swizzleWidth();
     }
 
     for (int y = 0; y < count; y++) {
         uint32_t lines = jpeg_read_scanlines(fDecoderMgr->dinfo(), &decodeDst, 1);
         size_t srcRowBytes = get_row_bytes(fDecoderMgr->dinfo());
         sk_msan_mark_initialized(decodeDst, decodeDst + srcRowBytes, "skbug.com/4550");
         if (0 == lines) {
             return y;
         }
 
         if (fSwizzler) {
             fSwizzler->swizzle(swizzleDst, decodeDst);
         }
 
         if (fColorXform) {
-            fColorXform->apply(dst, swizzleDst, dstInfo.width(), dstInfo.colorType(),
-                               kOpaque_SkAlphaType);
+            fColorXform->apply(dst, swizzleDst, dstWidth, dstInfo.colorType(), kOpaque_SkAlphaType);
             dst = SkTAddOffset<void>(dst, rowBytes);
         }
 
         decodeDst = SkTAddOffset<JSAMPLE>(decodeDst, decodeDstRowBytes);
         swizzleDst = SkTAddOffset<uint32_t>(swizzleDst, swizzleDstRowBytes);
     }
 
     return count;
 }
 
@@ skipping 45 matching lines @@
     int rows = this->readRows(dstInfo, dst, dstRowBytes, dstInfo.height());
     if (rows < dstInfo.height()) {
         *rowsDecoded = rows;
         return fDecoderMgr->returnFailure("Incomplete image data", kIncompleteInput);
     }
 
     return kSuccess;
 }
 
 void SkJpegCodec::allocateStorage(const SkImageInfo& dstInfo) {
+    int dstWidth = dstInfo.width();
+
     size_t swizzleBytes = 0;
     if (fSwizzler) {
         swizzleBytes = get_row_bytes(fDecoderMgr->dinfo());
+        dstWidth = fSwizzler->swizzleWidth();
         SkASSERT(!fColorXform || SkIsAlign4(swizzleBytes));
     }
 
     size_t xformBytes = 0;
     if (kRGBA_F16_SkColorType == dstInfo.colorType()) {
         SkASSERT(fColorXform);
-        xformBytes = dstInfo.width() * sizeof(uint32_t);
+        xformBytes = dstWidth * sizeof(uint32_t);
     }
 
     size_t totalBytes = swizzleBytes + xformBytes;
     if (totalBytes > 0) {
         fStorage.reset(totalBytes);
         fSwizzleSrcRow = (swizzleBytes > 0) ? fStorage.get() : nullptr;
         fColorXformSrcRow = (xformBytes > 0) ?
                 SkTAddOffset<uint32_t>(fStorage.get(), swizzleBytes) : nullptr;
     }
 }
@@ skipping 364 matching lines @@
 
         JDIMENSION linesRead = jpeg_read_raw_data(dinfo, yuv, numRowsPerBlock);
         if (linesRead < remainingRows) {
             // FIXME: Handle incomplete YUV decodes without signalling an error.
             return kInvalidInput;
         }
     }
 
     return kSuccess;
 }