--- /dev/null
+\r
+/* pngpread.c - read a png file in push mode\r
+ *\r
+ * Last changed in libpng 1.2.32 [September 18, 2008]\r
+ * For conditions of distribution and use, see copyright notice in png.h\r
+ * Copyright (c) 1998-2008 Glenn Randers-Pehrson\r
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)\r
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)\r
+ */\r
+\r
+#define PNG_INTERNAL\r
+#include "png.h"\r
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED\r
+\r
+/* push model modes */\r
+#define PNG_READ_SIG_MODE 0\r
+#define PNG_READ_CHUNK_MODE 1\r
+#define PNG_READ_IDAT_MODE 2\r
+#define PNG_SKIP_MODE 3\r
+#define PNG_READ_tEXt_MODE 4\r
+#define PNG_READ_zTXt_MODE 5\r
+#define PNG_READ_DONE_MODE 6\r
+#define PNG_READ_iTXt_MODE 7\r
+#define PNG_ERROR_MODE 8\r
+\r
+void PNGAPI\r
+png_process_data(png_structp png_ptr, png_infop info_ptr,\r
+ png_bytep buffer, png_size_t buffer_size)\r
+{\r
+ if (png_ptr == NULL || info_ptr == NULL) return;\r
+ png_push_restore_buffer(png_ptr, buffer, buffer_size);\r
+\r
+ while (png_ptr->buffer_size)\r
+ {\r
+ png_process_some_data(png_ptr, info_ptr);\r
+ }\r
+}\r
+\r
+/* What we do with the incoming data depends on what we were previously\r
+ * doing before we ran out of data...\r
+ */\r
+void /* PRIVATE */\r
+png_process_some_data(png_structp png_ptr, png_infop info_ptr)\r
+{\r
+ if (png_ptr == NULL) return;\r
+ switch (png_ptr->process_mode)\r
+ {\r
+ case PNG_READ_SIG_MODE:\r
+ {\r
+ png_push_read_sig(png_ptr, info_ptr);\r
+ break;\r
+ }\r
+ case PNG_READ_CHUNK_MODE:\r
+ {\r
+ png_push_read_chunk(png_ptr, info_ptr);\r
+ break;\r
+ }\r
+ case PNG_READ_IDAT_MODE:\r
+ {\r
+ png_push_read_IDAT(png_ptr);\r
+ break;\r
+ }\r
+#if defined(PNG_READ_tEXt_SUPPORTED)\r
+ case PNG_READ_tEXt_MODE:\r
+ {\r
+ png_push_read_tEXt(png_ptr, info_ptr);\r
+ break;\r
+ }\r
+#endif\r
+#if defined(PNG_READ_zTXt_SUPPORTED)\r
+ case PNG_READ_zTXt_MODE:\r
+ {\r
+ png_push_read_zTXt(png_ptr, info_ptr);\r
+ break;\r
+ }\r
+#endif\r
+#if defined(PNG_READ_iTXt_SUPPORTED)\r
+ case PNG_READ_iTXt_MODE:\r
+ {\r
+ png_push_read_iTXt(png_ptr, info_ptr);\r
+ break;\r
+ }\r
+#endif\r
+ case PNG_SKIP_MODE:\r
+ {\r
+ png_push_crc_finish(png_ptr);\r
+ break;\r
+ }\r
+ default:\r
+ {\r
+ png_ptr->buffer_size = 0;\r
+ break;\r
+ }\r
+ }\r
+}\r
+\r
+/* Read any remaining signature bytes from the stream and compare them with\r
+ * the correct PNG signature. It is possible that this routine is called\r
+ * with bytes already read from the signature, either because they have been\r
+ * checked by the calling application, or because of multiple calls to this\r
+ * routine.\r
+ */\r
+void /* PRIVATE */\r
+png_push_read_sig(png_structp png_ptr, png_infop info_ptr)\r
+{\r
+ png_size_t num_checked = png_ptr->sig_bytes,\r
+ num_to_check = 8 - num_checked;\r
+\r
+ if (png_ptr->buffer_size < num_to_check)\r
+ {\r
+ num_to_check = png_ptr->buffer_size;\r
+ }\r
+\r
+ png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),\r
+ num_to_check);\r
+ png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);\r
+\r
+ if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))\r
+ {\r
+ if (num_checked < 4 &&\r
+ png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))\r
+ png_error(png_ptr, "Not a PNG file");\r
+ else\r
+ png_error(png_ptr, "PNG file corrupted by ASCII conversion");\r
+ }\r
+ else\r
+ {\r
+ if (png_ptr->sig_bytes >= 8)\r
+ {\r
+ png_ptr->process_mode = PNG_READ_CHUNK_MODE;\r
+ }\r
+ }\r
+}\r
+\r
+void /* PRIVATE */\r
+png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_CONST PNG_IHDR;\r
+ PNG_CONST PNG_IDAT;\r
+ PNG_CONST PNG_IEND;\r
+ PNG_CONST PNG_PLTE;\r
+#if defined(PNG_READ_bKGD_SUPPORTED)\r
+ PNG_CONST PNG_bKGD;\r
+#endif\r
+#if defined(PNG_READ_cHRM_SUPPORTED)\r
+ PNG_CONST PNG_cHRM;\r
+#endif\r
+#if defined(PNG_READ_gAMA_SUPPORTED)\r
+ PNG_CONST PNG_gAMA;\r
+#endif\r
+#if defined(PNG_READ_hIST_SUPPORTED)\r
+ PNG_CONST PNG_hIST;\r
+#endif\r
+#if defined(PNG_READ_iCCP_SUPPORTED)\r
+ PNG_CONST PNG_iCCP;\r
+#endif\r
+#if defined(PNG_READ_iTXt_SUPPORTED)\r
+ PNG_CONST PNG_iTXt;\r
+#endif\r
+#if defined(PNG_READ_oFFs_SUPPORTED)\r
+ PNG_CONST PNG_oFFs;\r
+#endif\r
+#if defined(PNG_READ_pCAL_SUPPORTED)\r
+ PNG_CONST PNG_pCAL;\r
+#endif\r
+#if defined(PNG_READ_pHYs_SUPPORTED)\r
+ PNG_CONST PNG_pHYs;\r
+#endif\r
+#if defined(PNG_READ_sBIT_SUPPORTED)\r
+ PNG_CONST PNG_sBIT;\r
+#endif\r
+#if defined(PNG_READ_sCAL_SUPPORTED)\r
+ PNG_CONST PNG_sCAL;\r
+#endif\r
+#if defined(PNG_READ_sRGB_SUPPORTED)\r
+ PNG_CONST PNG_sRGB;\r
+#endif\r
+#if defined(PNG_READ_sPLT_SUPPORTED)\r
+ PNG_CONST PNG_sPLT;\r
+#endif\r
+#if defined(PNG_READ_tEXt_SUPPORTED)\r
+ PNG_CONST PNG_tEXt;\r
+#endif\r
+#if defined(PNG_READ_tIME_SUPPORTED)\r
+ PNG_CONST PNG_tIME;\r
+#endif\r
+#if defined(PNG_READ_tRNS_SUPPORTED)\r
+ PNG_CONST PNG_tRNS;\r
+#endif\r
+#if defined(PNG_READ_zTXt_SUPPORTED)\r
+ PNG_CONST PNG_zTXt;\r
+#endif\r
+#endif /* PNG_USE_LOCAL_ARRAYS */\r
+ /* First we make sure we have enough data for the 4 byte chunk name\r
+ * and the 4 byte chunk length before proceeding with decoding the\r
+ * chunk data. To fully decode each of these chunks, we also make\r
+ * sure we have enough data in the buffer for the 4 byte CRC at the\r
+ * end of every chunk (except IDAT, which is handled separately).\r
+ */\r
+ if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))\r
+ {\r
+ png_byte chunk_length[4];\r
+\r
+ if (png_ptr->buffer_size < 8)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+\r
+ png_push_fill_buffer(png_ptr, chunk_length, 4);\r
+ png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);\r
+ png_reset_crc(png_ptr);\r
+ png_crc_read(png_ptr, png_ptr->chunk_name, 4);\r
+ png_check_chunk_name(png_ptr, png_ptr->chunk_name);\r
+ png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;\r
+ }\r
+\r
+ if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))\r
+ if (png_ptr->mode & PNG_AFTER_IDAT)\r
+ png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;\r
+\r
+ if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))\r
+ {\r
+ if (png_ptr->push_length != 13)\r
+ png_error(png_ptr, "Invalid IHDR length");\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);\r
+\r
+ png_ptr->process_mode = PNG_READ_DONE_MODE;\r
+ png_push_have_end(png_ptr, info_ptr);\r
+ }\r
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED\r
+ else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))\r
+ png_ptr->mode |= PNG_HAVE_IDAT;\r
+ png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);\r
+ if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))\r
+ png_ptr->mode |= PNG_HAVE_PLTE;\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))\r
+ {\r
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))\r
+ png_error(png_ptr, "Missing IHDR before IDAT");\r
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&\r
+ !(png_ptr->mode & PNG_HAVE_PLTE))\r
+ png_error(png_ptr, "Missing PLTE before IDAT");\r
+ }\r
+ }\r
+#endif\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))\r
+ {\r
+ /* If we reach an IDAT chunk, this means we have read all of the\r
+ * header chunks, and we can start reading the image (or if this\r
+ * is called after the image has been read - we have an error).\r
+ */\r
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))\r
+ png_error(png_ptr, "Missing IHDR before IDAT");\r
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&\r
+ !(png_ptr->mode & PNG_HAVE_PLTE))\r
+ png_error(png_ptr, "Missing PLTE before IDAT");\r
+\r
+ if (png_ptr->mode & PNG_HAVE_IDAT)\r
+ {\r
+ if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))\r
+ if (png_ptr->push_length == 0)\r
+ return;\r
+\r
+ if (png_ptr->mode & PNG_AFTER_IDAT)\r
+ png_error(png_ptr, "Too many IDAT's found");\r
+ }\r
+\r
+ png_ptr->idat_size = png_ptr->push_length;\r
+ png_ptr->mode |= PNG_HAVE_IDAT;\r
+ png_ptr->process_mode = PNG_READ_IDAT_MODE;\r
+ png_push_have_info(png_ptr, info_ptr);\r
+ png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;\r
+ png_ptr->zstream.next_out = png_ptr->row_buf;\r
+ return;\r
+ }\r
+#if defined(PNG_READ_gAMA_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_sBIT_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_cHRM_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_sRGB_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_iCCP_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_sPLT_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_tRNS_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_bKGD_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_hIST_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_pHYs_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_oFFs_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_pCAL_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_sCAL_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_tIME_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_tEXt_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_zTXt_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+#if defined(PNG_READ_iTXt_SUPPORTED)\r
+ else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+#endif\r
+ else\r
+ {\r
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+ png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);\r
+ }\r
+\r
+ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;\r
+}\r
+\r
+void /* PRIVATE */\r
+png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)\r
+{\r
+ png_ptr->process_mode = PNG_SKIP_MODE;\r
+ png_ptr->skip_length = skip;\r
+}\r
+\r
+void /* PRIVATE */\r
+png_push_crc_finish(png_structp png_ptr)\r
+{\r
+ if (png_ptr->skip_length && png_ptr->save_buffer_size)\r
+ {\r
+ png_size_t save_size;\r
+\r
+ if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)\r
+ save_size = (png_size_t)png_ptr->skip_length;\r
+ else\r
+ save_size = png_ptr->save_buffer_size;\r
+\r
+ png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);\r
+\r
+ png_ptr->skip_length -= save_size;\r
+ png_ptr->buffer_size -= save_size;\r
+ png_ptr->save_buffer_size -= save_size;\r
+ png_ptr->save_buffer_ptr += save_size;\r
+ }\r
+ if (png_ptr->skip_length && png_ptr->current_buffer_size)\r
+ {\r
+ png_size_t save_size;\r
+\r
+ if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)\r
+ save_size = (png_size_t)png_ptr->skip_length;\r
+ else\r
+ save_size = png_ptr->current_buffer_size;\r
+\r
+ png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);\r
+\r
+ png_ptr->skip_length -= save_size;\r
+ png_ptr->buffer_size -= save_size;\r
+ png_ptr->current_buffer_size -= save_size;\r
+ png_ptr->current_buffer_ptr += save_size;\r
+ }\r
+ if (!png_ptr->skip_length)\r
+ {\r
+ if (png_ptr->buffer_size < 4)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+\r
+ png_crc_finish(png_ptr, 0);\r
+ png_ptr->process_mode = PNG_READ_CHUNK_MODE;\r
+ }\r
+}\r
+\r
+void PNGAPI\r
+png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)\r
+{\r
+ png_bytep ptr;\r
+\r
+ if (png_ptr == NULL) return;\r
+ ptr = buffer;\r
+ if (png_ptr->save_buffer_size)\r
+ {\r
+ png_size_t save_size;\r
+\r
+ if (length < png_ptr->save_buffer_size)\r
+ save_size = length;\r
+ else\r
+ save_size = png_ptr->save_buffer_size;\r
+\r
+ png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);\r
+ length -= save_size;\r
+ ptr += save_size;\r
+ png_ptr->buffer_size -= save_size;\r
+ png_ptr->save_buffer_size -= save_size;\r
+ png_ptr->save_buffer_ptr += save_size;\r
+ }\r
+ if (length && png_ptr->current_buffer_size)\r
+ {\r
+ png_size_t save_size;\r
+\r
+ if (length < png_ptr->current_buffer_size)\r
+ save_size = length;\r
+ else\r
+ save_size = png_ptr->current_buffer_size;\r
+\r
+ png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);\r
+ png_ptr->buffer_size -= save_size;\r
+ png_ptr->current_buffer_size -= save_size;\r
+ png_ptr->current_buffer_ptr += save_size;\r
+ }\r
+}\r
+\r
+void /* PRIVATE */\r
+png_push_save_buffer(png_structp png_ptr)\r
+{\r
+ if (png_ptr->save_buffer_size)\r
+ {\r
+ if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)\r
+ {\r
+ png_size_t i, istop;\r
+ png_bytep sp;\r
+ png_bytep dp;\r
+\r
+ istop = png_ptr->save_buffer_size;\r
+ for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;\r
+ i < istop; i++, sp++, dp++)\r
+ {\r
+ *dp = *sp;\r
+ }\r
+ }\r
+ }\r
+ if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >\r
+ png_ptr->save_buffer_max)\r
+ {\r
+ png_size_t new_max;\r
+ png_bytep old_buffer;\r
+\r
+ if (png_ptr->save_buffer_size > PNG_SIZE_MAX -\r
+ (png_ptr->current_buffer_size + 256))\r
+ {\r
+ png_error(png_ptr, "Potential overflow of save_buffer");\r
+ }\r
+ new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;\r
+ old_buffer = png_ptr->save_buffer;\r
+ png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)new_max);\r
+ png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);\r
+ png_free(png_ptr, old_buffer);\r
+ png_ptr->save_buffer_max = new_max;\r
+ }\r
+ if (png_ptr->current_buffer_size)\r
+ {\r
+ png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,\r
+ png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);\r
+ png_ptr->save_buffer_size += png_ptr->current_buffer_size;\r
+ png_ptr->current_buffer_size = 0;\r
+ }\r
+ png_ptr->save_buffer_ptr = png_ptr->save_buffer;\r
+ png_ptr->buffer_size = 0;\r
+}\r
+\r
+void /* PRIVATE */\r
+png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,\r
+ png_size_t buffer_length)\r
+{\r
+ png_ptr->current_buffer = buffer;\r
+ png_ptr->current_buffer_size = buffer_length;\r
+ png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;\r
+ png_ptr->current_buffer_ptr = png_ptr->current_buffer;\r
+}\r
+\r
+void /* PRIVATE */\r
+png_push_read_IDAT(png_structp png_ptr)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_CONST PNG_IDAT;\r
+#endif\r
+ if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))\r
+ {\r
+ png_byte chunk_length[4];\r
+\r
+ if (png_ptr->buffer_size < 8)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+\r
+ png_push_fill_buffer(png_ptr, chunk_length, 4);\r
+ png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);\r
+ png_reset_crc(png_ptr);\r
+ png_crc_read(png_ptr, png_ptr->chunk_name, 4);\r
+ png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;\r
+\r
+ if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))\r
+ {\r
+ png_ptr->process_mode = PNG_READ_CHUNK_MODE;\r
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))\r
+ png_error(png_ptr, "Not enough compressed data");\r
+ return;\r
+ }\r
+\r
+ png_ptr->idat_size = png_ptr->push_length;\r
+ }\r
+ if (png_ptr->idat_size && png_ptr->save_buffer_size)\r
+ {\r
+ png_size_t save_size;\r
+\r
+ if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)\r
+ {\r
+ save_size = (png_size_t)png_ptr->idat_size;\r
+ /* check for overflow */\r
+ if ((png_uint_32)save_size != png_ptr->idat_size)\r
+ png_error(png_ptr, "save_size overflowed in pngpread");\r
+ }\r
+ else\r
+ save_size = png_ptr->save_buffer_size;\r
+\r
+ png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);\r
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))\r
+ png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);\r
+ png_ptr->idat_size -= save_size;\r
+ png_ptr->buffer_size -= save_size;\r
+ png_ptr->save_buffer_size -= save_size;\r
+ png_ptr->save_buffer_ptr += save_size;\r
+ }\r
+ if (png_ptr->idat_size && png_ptr->current_buffer_size)\r
+ {\r
+ png_size_t save_size;\r
+\r
+ if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)\r
+ {\r
+ save_size = (png_size_t)png_ptr->idat_size;\r
+ /* check for overflow */\r
+ if ((png_uint_32)save_size != png_ptr->idat_size)\r
+ png_error(png_ptr, "save_size overflowed in pngpread");\r
+ }\r
+ else\r
+ save_size = png_ptr->current_buffer_size;\r
+\r
+ png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);\r
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))\r
+ png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);\r
+\r
+ png_ptr->idat_size -= save_size;\r
+ png_ptr->buffer_size -= save_size;\r
+ png_ptr->current_buffer_size -= save_size;\r
+ png_ptr->current_buffer_ptr += save_size;\r
+ }\r
+ if (!png_ptr->idat_size)\r
+ {\r
+ if (png_ptr->buffer_size < 4)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+\r
+ png_crc_finish(png_ptr, 0);\r
+ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;\r
+ png_ptr->mode |= PNG_AFTER_IDAT;\r
+ }\r
+}\r
+\r
+void /* PRIVATE */\r
+png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,\r
+ png_size_t buffer_length)\r
+{\r
+ int ret;\r
+\r
+ if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)\r
+ png_error(png_ptr, "Extra compression data");\r
+\r
+ png_ptr->zstream.next_in = buffer;\r
+ png_ptr->zstream.avail_in = (uInt)buffer_length;\r
+ for (;;)\r
+ {\r
+ ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);\r
+ if (ret != Z_OK)\r
+ {\r
+ if (ret == Z_STREAM_END)\r
+ {\r
+ if (png_ptr->zstream.avail_in)\r
+ png_error(png_ptr, "Extra compressed data");\r
+ if (!(png_ptr->zstream.avail_out))\r
+ {\r
+ png_push_process_row(png_ptr);\r
+ }\r
+\r
+ png_ptr->mode |= PNG_AFTER_IDAT;\r
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;\r
+ break;\r
+ }\r
+ else if (ret == Z_BUF_ERROR)\r
+ break;\r
+ else\r
+ png_error(png_ptr, "Decompression Error");\r
+ }\r
+ if (!(png_ptr->zstream.avail_out))\r
+ {\r
+ if ((\r
+#if defined(PNG_READ_INTERLACING_SUPPORTED)\r
+ png_ptr->interlaced && png_ptr->pass > 6) ||\r
+ (!png_ptr->interlaced &&\r
+#endif\r
+ png_ptr->row_number == png_ptr->num_rows))\r
+ {\r
+ if (png_ptr->zstream.avail_in)\r
+ png_warning(png_ptr, "Too much data in IDAT chunks");\r
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;\r
+ break;\r
+ }\r
+ png_push_process_row(png_ptr);\r
+ png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;\r
+ png_ptr->zstream.next_out = png_ptr->row_buf;\r
+ }\r
+ else\r
+ break;\r
+ }\r
+}\r
+\r
+void /* PRIVATE */\r
+png_push_process_row(png_structp png_ptr)\r
+{\r
+ png_ptr->row_info.color_type = png_ptr->color_type;\r
+ png_ptr->row_info.width = png_ptr->iwidth;\r
+ png_ptr->row_info.channels = png_ptr->channels;\r
+ png_ptr->row_info.bit_depth = png_ptr->bit_depth;\r
+ png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;\r
+\r
+ png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,\r
+ png_ptr->row_info.width);\r
+\r
+ png_read_filter_row(png_ptr, &(png_ptr->row_info),\r
+ png_ptr->row_buf + 1, png_ptr->prev_row + 1,\r
+ (int)(png_ptr->row_buf[0]));\r
+\r
+ png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,\r
+ png_ptr->rowbytes + 1);\r
+\r
+ if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))\r
+ png_do_read_transformations(png_ptr);\r
+\r
+#if defined(PNG_READ_INTERLACING_SUPPORTED)\r
+ /* blow up interlaced rows to full size */\r
+ if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))\r
+ {\r
+ if (png_ptr->pass < 6)\r
+/* old interface (pre-1.0.9):\r
+ png_do_read_interlace(&(png_ptr->row_info),\r
+ png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);\r
+ */\r
+ png_do_read_interlace(png_ptr);\r
+\r
+ switch (png_ptr->pass)\r
+ {\r
+ case 0:\r
+ {\r
+ int i;\r
+ for (i = 0; i < 8 && png_ptr->pass == 0; i++)\r
+ {\r
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);\r
+ png_read_push_finish_row(png_ptr); /* updates png_ptr->pass */\r
+ }\r
+ if (png_ptr->pass == 2) /* pass 1 might be empty */\r
+ {\r
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)\r
+ {\r
+ png_push_have_row(png_ptr, png_bytep_NULL);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ }\r
+ if (png_ptr->pass == 4 && png_ptr->height <= 4)\r
+ {\r
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)\r
+ {\r
+ png_push_have_row(png_ptr, png_bytep_NULL);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ }\r
+ if (png_ptr->pass == 6 && png_ptr->height <= 4)\r
+ {\r
+ png_push_have_row(png_ptr, png_bytep_NULL);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ break;\r
+ }\r
+ case 1:\r
+ {\r
+ int i;\r
+ for (i = 0; i < 8 && png_ptr->pass == 1; i++)\r
+ {\r
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ if (png_ptr->pass == 2) /* skip top 4 generated rows */\r
+ {\r
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)\r
+ {\r
+ png_push_have_row(png_ptr, png_bytep_NULL);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ case 2:\r
+ {\r
+ int i;\r
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)\r
+ {\r
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)\r
+ {\r
+ png_push_have_row(png_ptr, png_bytep_NULL);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ if (png_ptr->pass == 4) /* pass 3 might be empty */\r
+ {\r
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)\r
+ {\r
+ png_push_have_row(png_ptr, png_bytep_NULL);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ case 3:\r
+ {\r
+ int i;\r
+ for (i = 0; i < 4 && png_ptr->pass == 3; i++)\r
+ {\r
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ if (png_ptr->pass == 4) /* skip top two generated rows */\r
+ {\r
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)\r
+ {\r
+ png_push_have_row(png_ptr, png_bytep_NULL);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ case 4:\r
+ {\r
+ int i;\r
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)\r
+ {\r
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)\r
+ {\r
+ png_push_have_row(png_ptr, png_bytep_NULL);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ if (png_ptr->pass == 6) /* pass 5 might be empty */\r
+ {\r
+ png_push_have_row(png_ptr, png_bytep_NULL);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ break;\r
+ }\r
+ case 5:\r
+ {\r
+ int i;\r
+ for (i = 0; i < 2 && png_ptr->pass == 5; i++)\r
+ {\r
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ if (png_ptr->pass == 6) /* skip top generated row */\r
+ {\r
+ png_push_have_row(png_ptr, png_bytep_NULL);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ break;\r
+ }\r
+ case 6:\r
+ {\r
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);\r
+ png_read_push_finish_row(png_ptr);\r
+ if (png_ptr->pass != 6)\r
+ break;\r
+ png_push_have_row(png_ptr, png_bytep_NULL);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ png_push_have_row(png_ptr, png_ptr->row_buf + 1);\r
+ png_read_push_finish_row(png_ptr);\r
+ }\r
+}\r
+\r
+void /* PRIVATE */\r
+png_read_push_finish_row(png_structp png_ptr)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */\r
+\r
+ /* start of interlace block */\r
+ PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};\r
+\r
+ /* offset to next interlace block */\r
+ PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};\r
+\r
+ /* start of interlace block in the y direction */\r
+ PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};\r
+\r
+ /* offset to next interlace block in the y direction */\r
+ PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};\r
+\r
+ /* Height of interlace block. This is not currently used - if you need\r
+ * it, uncomment it here and in png.h\r
+ PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};\r
+ */\r
+#endif\r
+\r
+ png_ptr->row_number++;\r
+ if (png_ptr->row_number < png_ptr->num_rows)\r
+ return;\r
+\r
+ if (png_ptr->interlaced)\r
+ {\r
+ png_ptr->row_number = 0;\r
+ png_memset_check(png_ptr, png_ptr->prev_row, 0,\r
+ png_ptr->rowbytes + 1);\r
+ do\r
+ {\r
+ png_ptr->pass++;\r
+ if ((png_ptr->pass == 1 && png_ptr->width < 5) ||\r
+ (png_ptr->pass == 3 && png_ptr->width < 3) ||\r
+ (png_ptr->pass == 5 && png_ptr->width < 2))\r
+ png_ptr->pass++;\r
+\r
+ if (png_ptr->pass > 7)\r
+ png_ptr->pass--;\r
+ if (png_ptr->pass >= 7)\r
+ break;\r
+\r
+ png_ptr->iwidth = (png_ptr->width +\r
+ png_pass_inc[png_ptr->pass] - 1 -\r
+ png_pass_start[png_ptr->pass]) /\r
+ png_pass_inc[png_ptr->pass];\r
+\r
+ png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,\r
+ png_ptr->iwidth) + 1;\r
+\r
+ if (png_ptr->transformations & PNG_INTERLACE)\r
+ break;\r
+\r
+ png_ptr->num_rows = (png_ptr->height +\r
+ png_pass_yinc[png_ptr->pass] - 1 -\r
+ png_pass_ystart[png_ptr->pass]) /\r
+ png_pass_yinc[png_ptr->pass];\r
+\r
+ } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);\r
+ }\r
+}\r
+\r
+#if defined(PNG_READ_tEXt_SUPPORTED)\r
+void /* PRIVATE */\r
+png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32\r
+ length)\r
+{\r
+ if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))\r
+ {\r
+ png_error(png_ptr, "Out of place tEXt");\r
+ info_ptr = info_ptr; /* to quiet some compiler warnings */\r
+ }\r
+\r
+#ifdef PNG_MAX_MALLOC_64K\r
+ png_ptr->skip_length = 0; /* This may not be necessary */\r
+\r
+ if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */\r
+ {\r
+ png_warning(png_ptr, "tEXt chunk too large to fit in memory");\r
+ png_ptr->skip_length = length - (png_uint_32)65535L;\r
+ length = (png_uint_32)65535L;\r
+ }\r
+#endif\r
+\r
+ png_ptr->current_text = (png_charp)png_malloc(png_ptr,\r
+ (png_uint_32)(length + 1));\r
+ png_ptr->current_text[length] = '\0';\r
+ png_ptr->current_text_ptr = png_ptr->current_text;\r
+ png_ptr->current_text_size = (png_size_t)length;\r
+ png_ptr->current_text_left = (png_size_t)length;\r
+ png_ptr->process_mode = PNG_READ_tEXt_MODE;\r
+}\r
+\r
+void /* PRIVATE */\r
+png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)\r
+{\r
+ if (png_ptr->buffer_size && png_ptr->current_text_left)\r
+ {\r
+ png_size_t text_size;\r
+\r
+ if (png_ptr->buffer_size < png_ptr->current_text_left)\r
+ text_size = png_ptr->buffer_size;\r
+ else\r
+ text_size = png_ptr->current_text_left;\r
+ png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);\r
+ png_ptr->current_text_left -= text_size;\r
+ png_ptr->current_text_ptr += text_size;\r
+ }\r
+ if (!(png_ptr->current_text_left))\r
+ {\r
+ png_textp text_ptr;\r
+ png_charp text;\r
+ png_charp key;\r
+ int ret;\r
+\r
+ if (png_ptr->buffer_size < 4)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+\r
+ png_push_crc_finish(png_ptr);\r
+\r
+#if defined(PNG_MAX_MALLOC_64K)\r
+ if (png_ptr->skip_length)\r
+ return;\r
+#endif\r
+\r
+ key = png_ptr->current_text;\r
+\r
+ for (text = key; *text; text++)\r
+ /* empty loop */ ;\r
+\r
+ if (text < key + png_ptr->current_text_size)\r
+ text++;\r
+\r
+ text_ptr = (png_textp)png_malloc(png_ptr,\r
+ (png_uint_32)png_sizeof(png_text));\r
+ text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;\r
+ text_ptr->key = key;\r
+#ifdef PNG_iTXt_SUPPORTED\r
+ text_ptr->lang = NULL;\r
+ text_ptr->lang_key = NULL;\r
+#endif\r
+ text_ptr->text = text;\r
+\r
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);\r
+\r
+ png_free(png_ptr, key);\r
+ png_free(png_ptr, text_ptr);\r
+ png_ptr->current_text = NULL;\r
+\r
+ if (ret)\r
+ png_warning(png_ptr, "Insufficient memory to store text chunk.");\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_zTXt_SUPPORTED)\r
+void /* PRIVATE */\r
+png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32\r
+ length)\r
+{\r
+ if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))\r
+ {\r
+ png_error(png_ptr, "Out of place zTXt");\r
+ info_ptr = info_ptr; /* to quiet some compiler warnings */\r
+ }\r
+\r
+#ifdef PNG_MAX_MALLOC_64K\r
+ /* We can't handle zTXt chunks > 64K, since we don't have enough space\r
+ * to be able to store the uncompressed data. Actually, the threshold\r
+ * is probably around 32K, but it isn't as definite as 64K is.\r
+ */\r
+ if (length > (png_uint_32)65535L)\r
+ {\r
+ png_warning(png_ptr, "zTXt chunk too large to fit in memory");\r
+ png_push_crc_skip(png_ptr, length);\r
+ return;\r
+ }\r
+#endif\r
+\r
+ png_ptr->current_text = (png_charp)png_malloc(png_ptr,\r
+ (png_uint_32)(length + 1));\r
+ png_ptr->current_text[length] = '\0';\r
+ png_ptr->current_text_ptr = png_ptr->current_text;\r
+ png_ptr->current_text_size = (png_size_t)length;\r
+ png_ptr->current_text_left = (png_size_t)length;\r
+ png_ptr->process_mode = PNG_READ_zTXt_MODE;\r
+}\r
+\r
+void /* PRIVATE */\r
+png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)\r
+{\r
+ if (png_ptr->buffer_size && png_ptr->current_text_left)\r
+ {\r
+ png_size_t text_size;\r
+\r
+ if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)\r
+ text_size = png_ptr->buffer_size;\r
+ else\r
+ text_size = png_ptr->current_text_left;\r
+ png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);\r
+ png_ptr->current_text_left -= text_size;\r
+ png_ptr->current_text_ptr += text_size;\r
+ }\r
+ if (!(png_ptr->current_text_left))\r
+ {\r
+ png_textp text_ptr;\r
+ png_charp text;\r
+ png_charp key;\r
+ int ret;\r
+ png_size_t text_size, key_size;\r
+\r
+ if (png_ptr->buffer_size < 4)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+\r
+ png_push_crc_finish(png_ptr);\r
+\r
+ key = png_ptr->current_text;\r
+\r
+ for (text = key; *text; text++)\r
+ /* empty loop */ ;\r
+\r
+ /* zTXt can't have zero text */\r
+ if (text >= key + png_ptr->current_text_size)\r
+ {\r
+ png_ptr->current_text = NULL;\r
+ png_free(png_ptr, key);\r
+ return;\r
+ }\r
+\r
+ text++;\r
+\r
+ if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */\r
+ {\r
+ png_ptr->current_text = NULL;\r
+ png_free(png_ptr, key);\r
+ return;\r
+ }\r
+\r
+ text++;\r
+\r
+ png_ptr->zstream.next_in = (png_bytep )text;\r
+ png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size -\r
+ (text - key));\r
+ png_ptr->zstream.next_out = png_ptr->zbuf;\r
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;\r
+\r
+ key_size = text - key;\r
+ text_size = 0;\r
+ text = NULL;\r
+ ret = Z_STREAM_END;\r
+\r
+ while (png_ptr->zstream.avail_in)\r
+ {\r
+ ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);\r
+ if (ret != Z_OK && ret != Z_STREAM_END)\r
+ {\r
+ inflateReset(&png_ptr->zstream);\r
+ png_ptr->zstream.avail_in = 0;\r
+ png_ptr->current_text = NULL;\r
+ png_free(png_ptr, key);\r
+ png_free(png_ptr, text);\r
+ return;\r
+ }\r
+ if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)\r
+ {\r
+ if (text == NULL)\r
+ {\r
+ text = (png_charp)png_malloc(png_ptr,\r
+ (png_uint_32)(png_ptr->zbuf_size\r
+ - png_ptr->zstream.avail_out + key_size + 1));\r
+ png_memcpy(text + key_size, png_ptr->zbuf,\r
+ png_ptr->zbuf_size - png_ptr->zstream.avail_out);\r
+ png_memcpy(text, key, key_size);\r
+ text_size = key_size + png_ptr->zbuf_size -\r
+ png_ptr->zstream.avail_out;\r
+ *(text + text_size) = '\0';\r
+ }\r
+ else\r
+ {\r
+ png_charp tmp;\r
+\r
+ tmp = text;\r
+ text = (png_charp)png_malloc(png_ptr, text_size +\r
+ (png_uint_32)(png_ptr->zbuf_size \r
+ - png_ptr->zstream.avail_out + 1));\r
+ png_memcpy(text, tmp, text_size);\r
+ png_free(png_ptr, tmp);\r
+ png_memcpy(text + text_size, png_ptr->zbuf,\r
+ png_ptr->zbuf_size - png_ptr->zstream.avail_out);\r
+ text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;\r
+ *(text + text_size) = '\0';\r
+ }\r
+ if (ret != Z_STREAM_END)\r
+ {\r
+ png_ptr->zstream.next_out = png_ptr->zbuf;\r
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;\r
+ }\r
+ }\r
+ else\r
+ {\r
+ break;\r
+ }\r
+\r
+ if (ret == Z_STREAM_END)\r
+ break;\r
+ }\r
+\r
+ inflateReset(&png_ptr->zstream);\r
+ png_ptr->zstream.avail_in = 0;\r
+\r
+ if (ret != Z_STREAM_END)\r
+ {\r
+ png_ptr->current_text = NULL;\r
+ png_free(png_ptr, key);\r
+ png_free(png_ptr, text);\r
+ return;\r
+ }\r
+\r
+ png_ptr->current_text = NULL;\r
+ png_free(png_ptr, key);\r
+ key = text;\r
+ text += key_size;\r
+\r
+ text_ptr = (png_textp)png_malloc(png_ptr,\r
+ (png_uint_32)png_sizeof(png_text));\r
+ text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;\r
+ text_ptr->key = key;\r
+#ifdef PNG_iTXt_SUPPORTED\r
+ text_ptr->lang = NULL;\r
+ text_ptr->lang_key = NULL;\r
+#endif\r
+ text_ptr->text = text;\r
+\r
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);\r
+\r
+ png_free(png_ptr, key);\r
+ png_free(png_ptr, text_ptr);\r
+\r
+ if (ret)\r
+ png_warning(png_ptr, "Insufficient memory to store text chunk.");\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_iTXt_SUPPORTED)\r
+void /* PRIVATE */\r
+png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32\r
+ length)\r
+{\r
+ if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))\r
+ {\r
+ png_error(png_ptr, "Out of place iTXt");\r
+ info_ptr = info_ptr; /* to quiet some compiler warnings */\r
+ }\r
+\r
+#ifdef PNG_MAX_MALLOC_64K\r
+ png_ptr->skip_length = 0; /* This may not be necessary */\r
+\r
+ if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */\r
+ {\r
+ png_warning(png_ptr, "iTXt chunk too large to fit in memory");\r
+ png_ptr->skip_length = length - (png_uint_32)65535L;\r
+ length = (png_uint_32)65535L;\r
+ }\r
+#endif\r
+\r
+ png_ptr->current_text = (png_charp)png_malloc(png_ptr,\r
+ (png_uint_32)(length + 1));\r
+ png_ptr->current_text[length] = '\0';\r
+ png_ptr->current_text_ptr = png_ptr->current_text;\r
+ png_ptr->current_text_size = (png_size_t)length;\r
+ png_ptr->current_text_left = (png_size_t)length;\r
+ png_ptr->process_mode = PNG_READ_iTXt_MODE;\r
+}\r
+\r
+void /* PRIVATE */\r
+png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)\r
+{\r
+\r
+ if (png_ptr->buffer_size && png_ptr->current_text_left)\r
+ {\r
+ png_size_t text_size;\r
+\r
+ if (png_ptr->buffer_size < png_ptr->current_text_left)\r
+ text_size = png_ptr->buffer_size;\r
+ else\r
+ text_size = png_ptr->current_text_left;\r
+ png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);\r
+ png_ptr->current_text_left -= text_size;\r
+ png_ptr->current_text_ptr += text_size;\r
+ }\r
+ if (!(png_ptr->current_text_left))\r
+ {\r
+ png_textp text_ptr;\r
+ png_charp key;\r
+ int comp_flag;\r
+ png_charp lang;\r
+ png_charp lang_key;\r
+ png_charp text;\r
+ int ret;\r
+\r
+ if (png_ptr->buffer_size < 4)\r
+ {\r
+ png_push_save_buffer(png_ptr);\r
+ return;\r
+ }\r
+\r
+ png_push_crc_finish(png_ptr);\r
+\r
+#if defined(PNG_MAX_MALLOC_64K)\r
+ if (png_ptr->skip_length)\r
+ return;\r
+#endif\r
+\r
+ key = png_ptr->current_text;\r
+\r
+ for (lang = key; *lang; lang++)\r
+ /* empty loop */ ;\r
+\r
+ if (lang < key + png_ptr->current_text_size - 3)\r
+ lang++;\r
+\r
+ comp_flag = *lang++;\r
+ lang++; /* skip comp_type, always zero */\r
+\r
+ for (lang_key = lang; *lang_key; lang_key++)\r
+ /* empty loop */ ;\r
+ lang_key++; /* skip NUL separator */\r
+\r
+ text=lang_key;\r
+ if (lang_key < key + png_ptr->current_text_size - 1)\r
+ {\r
+ for (; *text; text++)\r
+ /* empty loop */ ;\r
+ }\r
+\r
+ if (text < key + png_ptr->current_text_size)\r
+ text++;\r
+\r
+ text_ptr = (png_textp)png_malloc(png_ptr,\r
+ (png_uint_32)png_sizeof(png_text));\r
+ text_ptr->compression = comp_flag + 2;\r
+ text_ptr->key = key;\r
+ text_ptr->lang = lang;\r
+ text_ptr->lang_key = lang_key;\r
+ text_ptr->text = text;\r
+ text_ptr->text_length = 0;\r
+ text_ptr->itxt_length = png_strlen(text);\r
+\r
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);\r
+\r
+ png_ptr->current_text = NULL;\r
+\r
+ png_free(png_ptr, text_ptr);\r
+ if (ret)\r
+ png_warning(png_ptr, "Insufficient memory to store iTXt chunk.");\r
+ }\r
+}\r
+#endif\r
+\r
+/* This function is called when we haven't found a handler for this\r
+ * chunk. If there isn't a problem with the chunk itself (ie a bad chunk\r
+ * name or a critical chunk), the chunk is (currently) silently ignored.\r
+ */\r
+void /* PRIVATE */\r
+png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32\r
+ length)\r
+{\r
+ png_uint_32 skip = 0;\r
+\r
+ if (!(png_ptr->chunk_name[0] & 0x20))\r
+ {\r
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)\r
+ if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=\r
+ PNG_HANDLE_CHUNK_ALWAYS\r
+#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)\r
+ && png_ptr->read_user_chunk_fn == NULL\r
+#endif\r
+ )\r
+#endif\r
+ png_chunk_error(png_ptr, "unknown critical chunk");\r
+\r
+ info_ptr = info_ptr; /* to quiet some compiler warnings */\r
+ }\r
+\r
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)\r
+ if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)\r
+ {\r
+#ifdef PNG_MAX_MALLOC_64K\r
+ if (length > (png_uint_32)65535L)\r
+ {\r
+ png_warning(png_ptr, "unknown chunk too large to fit in memory");\r
+ skip = length - (png_uint_32)65535L;\r
+ length = (png_uint_32)65535L;\r
+ }\r
+#endif\r
+ png_memcpy((png_charp)png_ptr->unknown_chunk.name,\r
+ (png_charp)png_ptr->chunk_name, \r
+ png_sizeof(png_ptr->unknown_chunk.name));\r
+ png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1]\r
+ = '\0';\r
+\r
+ png_ptr->unknown_chunk.size = (png_size_t)length;\r
+ if (length == 0)\r
+ png_ptr->unknown_chunk.data = NULL;\r
+ else\r
+ {\r
+ png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)length);\r
+ png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);\r
+ }\r
+#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)\r
+ if (png_ptr->read_user_chunk_fn != NULL)\r
+ {\r
+ /* callback to user unknown chunk handler */\r
+ int ret;\r
+ ret = (*(png_ptr->read_user_chunk_fn))\r
+ (png_ptr, &png_ptr->unknown_chunk);\r
+ if (ret < 0)\r
+ png_chunk_error(png_ptr, "error in user chunk");\r
+ if (ret == 0)\r
+ {\r
+ if (!(png_ptr->chunk_name[0] & 0x20))\r
+ if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=\r
+ PNG_HANDLE_CHUNK_ALWAYS)\r
+ png_chunk_error(png_ptr, "unknown critical chunk");\r
+ png_set_unknown_chunks(png_ptr, info_ptr,\r
+ &png_ptr->unknown_chunk, 1);\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);\r
+ png_free(png_ptr, png_ptr->unknown_chunk.data);\r
+ png_ptr->unknown_chunk.data = NULL;\r
+ }\r
+ else\r
+#endif\r
+ skip=length;\r
+ png_push_crc_skip(png_ptr, skip);\r
+}\r
+\r
+void /* PRIVATE */\r
+png_push_have_info(png_structp png_ptr, png_infop info_ptr)\r
+{\r
+ if (png_ptr->info_fn != NULL)\r
+ (*(png_ptr->info_fn))(png_ptr, info_ptr);\r
+}\r
+\r
+void /* PRIVATE */\r
+png_push_have_end(png_structp png_ptr, png_infop info_ptr)\r
+{\r
+ if (png_ptr->end_fn != NULL)\r
+ (*(png_ptr->end_fn))(png_ptr, info_ptr);\r
+}\r
+\r
+void /* PRIVATE */\r
+png_push_have_row(png_structp png_ptr, png_bytep row)\r
+{\r
+ if (png_ptr->row_fn != NULL)\r
+ (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,\r
+ (int)png_ptr->pass);\r
+}\r
+\r
+void PNGAPI\r
+png_progressive_combine_row (png_structp png_ptr,\r
+ png_bytep old_row, png_bytep new_row)\r
+{\r
+#ifdef PNG_USE_LOCAL_ARRAYS\r
+ PNG_CONST int FARDATA png_pass_dsp_mask[7] =\r
+ {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};\r
+#endif\r
+ if (png_ptr == NULL) return;\r
+ if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */\r
+ png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);\r
+}\r
+\r
+void PNGAPI\r
+png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,\r
+ png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,\r
+ png_progressive_end_ptr end_fn)\r
+{\r
+ if (png_ptr == NULL) return;\r
+ png_ptr->info_fn = info_fn;\r
+ png_ptr->row_fn = row_fn;\r
+ png_ptr->end_fn = end_fn;\r
+\r
+ png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);\r
+}\r
+\r
+png_voidp PNGAPI\r
+png_get_progressive_ptr(png_structp png_ptr)\r
+{\r
+ if (png_ptr == NULL) return (NULL);\r
+ return png_ptr->io_ptr;\r
+}\r
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */\r
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