Patch fix for "Add jpeg_skip_scanlines() API to libjpeg-turbo"

jdhuff.c

 /*
  * jdhuff.c
  *
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1991-1997, Thomas G. Lane.
  * libjpeg-turbo Modifications:
  * Copyright (C) 2009-2011, 2015, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README file.
  *
  * This file contains Huffman entropy decoding routines.
@@ skipping 642 matching lines @@
   int blkn;
   savable_state state;
   /* Outer loop handles each block in the MCU */
 
   /* Load up working state */
   BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
   buffer = (JOCTET *) br_state.next_input_byte;
   ASSIGN_STATE(state, entropy->saved);
 
   for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
-    JBLOCKROW block = MCU_data[blkn];
+    JBLOCKROW block = MCU_data ? MCU_data[blkn] : NULL;

[Noel Gordon, 2015/08/12 00:39:22]

Confusing: this change was in the original submit, right?

https://codereview.chromium.org/1271803002/diff/1/jdhuff.c

Anyho, seems you have included the line now, LGTM. 

     d_derived_tbl * dctbl = entropy->dc_cur_tbls[blkn];
     d_derived_tbl * actbl = entropy->ac_cur_tbls[blkn];
     register int s, k, r, l;
 
     HUFF_DECODE_FAST(s, l, dctbl, slow_decode_mcu);
     if (s) {
       FILL_BIT_BUFFER_FAST
       r = GET_BITS(s);
       s = HUFF_EXTEND(r, s);
     }
@@ skipping 130 matching lines @@
                                 SIZEOF(huff_entropy_decoder));
   cinfo->entropy = (struct jpeg_entropy_decoder *) entropy;
   entropy->pub.start_pass = start_pass_huff_decoder;
   entropy->pub.decode_mcu = decode_mcu;
 
   /* Mark tables unallocated */
   for (i = 0; i < NUM_HUFF_TBLS; i++) {
     entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL;
   }
 }