commit b0277d0706e596e9a1dd889903f8ceb2680bcadb
author Sireesh Tripurari <sireesh.tripurari@linaro.org> Fri May 09 15:39:12 2014 +0530
committer Sireesh Tripurari <sireesh.tripurari@linaro.org> Fri May 09 12:02:04 2014 +0000
tree e0d91a166486805affa71e8cb1b92fa073b06776
parent b478e66e7c2621eef5f465e4629ce642db00716b

libpng 1.6.10 - Merge seekable png patch

Change-Id: I3aa6d8775b884f719375c5aaa458a5c27c120b38

pngrutil.c

diff --git a/pngrutil.c b/pngrutil.c
index 98e9524..9638bed 100644
--- a/pngrutil.c
+++ b/pngrutil.c
@@ -235,6 +235,33 @@
    return (0);
 }
 
+#ifdef PNG_INDEX_SUPPORTED
+int /* PRIVATE */
+png_opt_crc_finish(png_structrp png_ptr, png_uint_32 skip)
+{
+   while (skip > 0)
+   {
+      png_uint_32 len;
+      png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
+
+      len = (sizeof tmpbuf);
+      if (len > skip)
+         len = skip;
+      skip -= len;
+
+      png_crc_read(png_ptr, tmpbuf, len);
+   }
+
+   if (png_crc_error(png_ptr))
+   {
+      png_chunk_warning(png_ptr, "CRC error");
+      return (1);
+   }
+
+   return (0);
+}
+#endif
+
 /* Compare the CRC stored in the PNG file with that calculated by libpng from
  * the data it has read thus far.
  */
@@ -3957,6 +3984,12 @@
 
          while (png_ptr->idat_size == 0)
          {
+#ifdef PNG_INDEX_SUPPORTED
+            if (png_ptr->index) {
+               png_opt_crc_finish(png_ptr, 0);
+               png_ptr->index->stream_idat_position = png_ptr->total_data_read;
+            } else
+#endif
             png_crc_finish(png_ptr, 0);
 
             png_ptr->idat_size = png_read_chunk_header(png_ptr);
@@ -4036,6 +4069,9 @@
       }
 
       if (ret != Z_OK)
+#ifdef PNG_INDEX_SUPPORTED
+        if (png_ptr->index && png_ptr->row_number != png_ptr->height - 1)
+#endif
       {
          png_zstream_error(png_ptr, ret);
 
@@ -4111,6 +4147,27 @@
    }
 }
 
+#ifdef PNG_INDEX_SUPPORTED
+void /* PRIVATE */
+png_set_interlaced_pass(png_structp png_ptr, int pass)
+{
+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+   /* Start of interlace block */
+   PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
+   /* Offset to next interlace block */
+   PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+   /* Start of interlace block in the y direction */
+   PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
+   /* Offset to next interlace block in the y direction */
+   PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+   png_ptr->pass = pass;
+   png_ptr->iwidth = (png_ptr->width +
+         png_pass_inc[png_ptr->pass] - 1 -
+         png_pass_start[png_ptr->pass]) /
+      png_pass_inc[png_ptr->pass];
+}
+#endif
+
 void /* PRIVATE */
 png_read_finish_row(png_structrp png_ptr)
 {