2296
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1
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2 /* pngerror.c - stub functions for i/o and memory allocation
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3 *
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4 * Last changed in libpng 1.6.10 [March 6, 2014]
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5 * Copyright (c) 1998-2014 Glenn Randers-Pehrson
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6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
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7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
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8 *
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9 * This code is released under the libpng license.
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10 * For conditions of distribution and use, see the disclaimer
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11 * and license in png.h
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12 *
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13 * This file provides a location for all error handling. Users who
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14 * need special error handling are expected to write replacement functions
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15 * and use png_set_error_fn() to use those functions. See the instructions
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16 * at each function.
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17 */
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18
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19 #include "pngpriv.h"
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20
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21 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
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22
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23 static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr,
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24 png_const_charp error_message)),PNG_NORETURN);
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25
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26 #ifdef PNG_WARNINGS_SUPPORTED
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27 static void /* PRIVATE */
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28 png_default_warning PNGARG((png_const_structrp png_ptr,
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29 png_const_charp warning_message));
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30 #endif /* PNG_WARNINGS_SUPPORTED */
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31
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32 /* This function is called whenever there is a fatal error. This function
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33 * should not be changed. If there is a need to handle errors differently,
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34 * you should supply a replacement error function and use png_set_error_fn()
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35 * to replace the error function at run-time.
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36 */
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37 #ifdef PNG_ERROR_TEXT_SUPPORTED
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38 PNG_FUNCTION(void,PNGAPI
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39 png_error,(png_const_structrp png_ptr, png_const_charp error_message),
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40 PNG_NORETURN)
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41 {
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42 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
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43 char msg[16];
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44 if (png_ptr != NULL)
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45 {
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46 if (png_ptr->flags&
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47 (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
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48 {
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49 if (*error_message == PNG_LITERAL_SHARP)
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50 {
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51 /* Strip "#nnnn " from beginning of error message. */
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52 int offset;
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53 for (offset = 1; offset<15; offset++)
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54 if (error_message[offset] == ' ')
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55 break;
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56
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57 if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
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58 {
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59 int i;
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60 for (i = 0; i < offset - 1; i++)
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61 msg[i] = error_message[i + 1];
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62 msg[i - 1] = '\0';
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63 error_message = msg;
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64 }
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65
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66 else
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67 error_message += offset;
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68 }
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69
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70 else
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71 {
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72 if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
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73 {
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74 msg[0] = '0';
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75 msg[1] = '\0';
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76 error_message = msg;
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77 }
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78 }
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79 }
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80 }
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81 #endif
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82 if (png_ptr != NULL && png_ptr->error_fn != NULL)
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83 (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
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84 error_message);
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85
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86 /* If the custom handler doesn't exist, or if it returns,
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87 use the default handler, which will not return. */
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88 png_default_error(png_ptr, error_message);
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89 }
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90 #else
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91 PNG_FUNCTION(void,PNGAPI
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92 png_err,(png_const_structrp png_ptr),PNG_NORETURN)
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93 {
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94 /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed
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95 * erroneously as '\0', instead of the empty string "". This was
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96 * apparently an error, introduced in libpng-1.2.20, and png_default_error
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97 * will crash in this case.
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98 */
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99 if (png_ptr != NULL && png_ptr->error_fn != NULL)
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100 (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), "");
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101
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102 /* If the custom handler doesn't exist, or if it returns,
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103 use the default handler, which will not return. */
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104 png_default_error(png_ptr, "");
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105 }
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106 #endif /* PNG_ERROR_TEXT_SUPPORTED */
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107
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108 /* Utility to safely appends strings to a buffer. This never errors out so
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109 * error checking is not required in the caller.
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110 */
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111 size_t
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112 png_safecat(png_charp buffer, size_t bufsize, size_t pos,
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113 png_const_charp string)
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114 {
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115 if (buffer != NULL && pos < bufsize)
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116 {
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117 if (string != NULL)
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118 while (*string != '\0' && pos < bufsize-1)
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119 buffer[pos++] = *string++;
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120
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121 buffer[pos] = '\0';
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122 }
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123
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124 return pos;
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125 }
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126
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127 #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
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128 /* Utility to dump an unsigned value into a buffer, given a start pointer and
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129 * and end pointer (which should point just *beyond* the end of the buffer!)
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130 * Returns the pointer to the start of the formatted string.
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131 */
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132 png_charp
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133 png_format_number(png_const_charp start, png_charp end, int format,
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134 png_alloc_size_t number)
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135 {
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136 int count = 0; /* number of digits output */
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137 int mincount = 1; /* minimum number required */
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138 int output = 0; /* digit output (for the fixed point format) */
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139
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140 *--end = '\0';
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141
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142 /* This is written so that the loop always runs at least once, even with
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143 * number zero.
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144 */
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145 while (end > start && (number != 0 || count < mincount))
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146 {
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147
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148 static const char digits[] = "0123456789ABCDEF";
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149
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150 switch (format)
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151 {
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152 case PNG_NUMBER_FORMAT_fixed:
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153 /* Needs five digits (the fraction) */
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154 mincount = 5;
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155 if (output || number % 10 != 0)
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156 {
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157 *--end = digits[number % 10];
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158 output = 1;
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159 }
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160 number /= 10;
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161 break;
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162
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163 case PNG_NUMBER_FORMAT_02u:
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164 /* Expects at least 2 digits. */
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165 mincount = 2;
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166 /* FALL THROUGH */
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167
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168 case PNG_NUMBER_FORMAT_u:
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169 *--end = digits[number % 10];
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170 number /= 10;
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171 break;
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172
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173 case PNG_NUMBER_FORMAT_02x:
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174 /* This format expects at least two digits */
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175 mincount = 2;
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176 /* FALL THROUGH */
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177
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178 case PNG_NUMBER_FORMAT_x:
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179 *--end = digits[number & 0xf];
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180 number >>= 4;
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181 break;
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182
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183 default: /* an error */
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184 number = 0;
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185 break;
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186 }
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187
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188 /* Keep track of the number of digits added */
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189 ++count;
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190
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191 /* Float a fixed number here: */
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192 if (format == PNG_NUMBER_FORMAT_fixed) if (count == 5) if (end > start)
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193 {
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194 /* End of the fraction, but maybe nothing was output? In that case
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195 * drop the decimal point. If the number is a true zero handle that
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196 * here.
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197 */
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198 if (output)
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199 *--end = '.';
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200 else if (number == 0) /* and !output */
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201 *--end = '0';
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202 }
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203 }
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204
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205 return end;
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206 }
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207 #endif
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208
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209 #ifdef PNG_WARNINGS_SUPPORTED
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210 /* This function is called whenever there is a non-fatal error. This function
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211 * should not be changed. If there is a need to handle warnings differently,
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212 * you should supply a replacement warning function and use
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213 * png_set_error_fn() to replace the warning function at run-time.
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214 */
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215 void PNGAPI
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216 png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
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217 {
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218 int offset = 0;
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219 if (png_ptr != NULL)
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220 {
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221 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
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222 if (png_ptr->flags&
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223 (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
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224 #endif
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225 {
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226 if (*warning_message == PNG_LITERAL_SHARP)
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227 {
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228 for (offset = 1; offset < 15; offset++)
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229 if (warning_message[offset] == ' ')
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230 break;
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231 }
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232 }
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233 }
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234 if (png_ptr != NULL && png_ptr->warning_fn != NULL)
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235 (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr),
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236 warning_message + offset);
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237 else
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238 png_default_warning(png_ptr, warning_message + offset);
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239 }
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240
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241 /* These functions support 'formatted' warning messages with up to
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242 * PNG_WARNING_PARAMETER_COUNT parameters. In the format string the parameter
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243 * is introduced by @<number>, where 'number' starts at 1. This follows the
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244 * standard established by X/Open for internationalizable error messages.
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245 */
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246 void
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247 png_warning_parameter(png_warning_parameters p, int number,
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248 png_const_charp string)
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249 {
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250 if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)
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251 (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);
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252 }
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253
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254 void
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255 png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
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256 png_alloc_size_t value)
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257 {
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258 char buffer[PNG_NUMBER_BUFFER_SIZE];
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259 png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
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260 }
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261
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262 void
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263 png_warning_parameter_signed(png_warning_parameters p, int number, int format,
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264 png_int_32 value)
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265 {
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266 png_alloc_size_t u;
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267 png_charp str;
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268 char buffer[PNG_NUMBER_BUFFER_SIZE];
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269
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270 /* Avoid overflow by doing the negate in a png_alloc_size_t: */
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271 u = (png_alloc_size_t)value;
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272 if (value < 0)
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273 u = ~u + 1;
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274
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275 str = PNG_FORMAT_NUMBER(buffer, format, u);
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276
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277 if (value < 0 && str > buffer)
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278 *--str = '-';
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279
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280 png_warning_parameter(p, number, str);
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281 }
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282
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283 void
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284 png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
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285 png_const_charp message)
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286 {
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287 /* The internal buffer is just 192 bytes - enough for all our messages,
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288 * overflow doesn't happen because this code checks! If someone figures
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289 * out how to send us a message longer than 192 bytes, all that will
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290 * happen is that the message will be truncated appropriately.
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291 */
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292 size_t i = 0; /* Index in the msg[] buffer: */
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293 char msg[192];
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294
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295 /* Each iteration through the following loop writes at most one character
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296 * to msg[i++] then returns here to validate that there is still space for
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297 * the trailing '\0'. It may (in the case of a parameter) read more than
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298 * one character from message[]; it must check for '\0' and continue to the
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299 * test if it finds the end of string.
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300 */
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301 while (i<(sizeof msg)-1 && *message != '\0')
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302 {
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303 /* '@' at end of string is now just printed (previously it was skipped);
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304 * it is an error in the calling code to terminate the string with @.
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305 */
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306 if (p != NULL && *message == '@' && message[1] != '\0')
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307 {
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308 int parameter_char = *++message; /* Consume the '@' */
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309 static const char valid_parameters[] = "123456789";
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310 int parameter = 0;
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311
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312 /* Search for the parameter digit, the index in the string is the
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313 * parameter to use.
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314 */
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315 while (valid_parameters[parameter] != parameter_char &&
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316 valid_parameters[parameter] != '\0')
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317 ++parameter;
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318
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319 /* If the parameter digit is out of range it will just get printed. */
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320 if (parameter < PNG_WARNING_PARAMETER_COUNT)
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321 {
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322 /* Append this parameter */
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323 png_const_charp parm = p[parameter];
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324 png_const_charp pend = p[parameter] + (sizeof p[parameter]);
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325
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326 /* No need to copy the trailing '\0' here, but there is no guarantee
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327 * that parm[] has been initialized, so there is no guarantee of a
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328 * trailing '\0':
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329 */
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330 while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend)
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331 msg[i++] = *parm++;
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332
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333 /* Consume the parameter digit too: */
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334 ++message;
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335 continue;
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336 }
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337
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338 /* else not a parameter and there is a character after the @ sign; just
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339 * copy that. This is known not to be '\0' because of the test above.
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340 */
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341 }
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342
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343 /* At this point *message can't be '\0', even in the bad parameter case
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344 * above where there is a lone '@' at the end of the message string.
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345 */
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346 msg[i++] = *message++;
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347 }
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348
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349 /* i is always less than (sizeof msg), so: */
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350 msg[i] = '\0';
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351
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352 /* And this is the formatted message. It may be larger than
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353 * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these
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354 * are not (currently) formatted.
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355 */
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356 png_warning(png_ptr, msg);
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357 }
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358 #endif /* PNG_WARNINGS_SUPPORTED */
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359
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360 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
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361 void PNGAPI
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362 png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
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363 {
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364 if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
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365 {
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366 # ifdef PNG_READ_SUPPORTED
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367 if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
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368 png_ptr->chunk_name != 0)
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369 png_chunk_warning(png_ptr, error_message);
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370 else
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371 # endif
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372 png_warning(png_ptr, error_message);
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373 }
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374
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375 else
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376 {
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377 # ifdef PNG_READ_SUPPORTED
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378 if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
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379 png_ptr->chunk_name != 0)
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380 png_chunk_error(png_ptr, error_message);
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381 else
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382 # endif
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383 png_error(png_ptr, error_message);
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384 }
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385
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386 # ifndef PNG_ERROR_TEXT_SUPPORTED
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387 PNG_UNUSED(error_message)
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388 # endif
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389 }
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390
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391 void /* PRIVATE */
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392 png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
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393 {
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394 if (png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN)
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395 png_warning(png_ptr, error_message);
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396 else
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397 png_error(png_ptr, error_message);
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398
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399 # ifndef PNG_ERROR_TEXT_SUPPORTED
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400 PNG_UNUSED(error_message)
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401 # endif
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402 }
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403
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404 void /* PRIVATE */
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405 png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
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406 {
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407 if (png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN)
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408 png_warning(png_ptr, error_message);
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409 else
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410 png_error(png_ptr, error_message);
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411
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412 # ifndef PNG_ERROR_TEXT_SUPPORTED
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413 PNG_UNUSED(error_message)
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414 # endif
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415 }
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416 #endif /* BENIGN_ERRORS */
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417
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418 /* These utilities are used internally to build an error message that relates
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419 * to the current chunk. The chunk name comes from png_ptr->chunk_name,
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420 * this is used to prefix the message. The message is limited in length
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421 * to 63 bytes, the name characters are output as hex digits wrapped in []
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422 * if the character is invalid.
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423 */
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424 #define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
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425 static PNG_CONST char png_digit[16] = {
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426 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
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427 'A', 'B', 'C', 'D', 'E', 'F'
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428 };
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429
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430 #define PNG_MAX_ERROR_TEXT 196 /* Currently limited be profile_error in png.c */
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431 #if defined(PNG_WARNINGS_SUPPORTED) || \
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432 (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))
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433 static void /* PRIVATE */
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434 png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
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435 error_message)
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436 {
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437 png_uint_32 chunk_name = png_ptr->chunk_name;
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438 int iout = 0, ishift = 24;
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439
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440 while (ishift >= 0)
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441 {
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442 int c = (int)(chunk_name >> ishift) & 0xff;
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443
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444 ishift -= 8;
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445 if (isnonalpha(c))
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446 {
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447 buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
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448 buffer[iout++] = png_digit[(c & 0xf0) >> 4];
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449 buffer[iout++] = png_digit[c & 0x0f];
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450 buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
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451 }
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452
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453 else
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454 {
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455 buffer[iout++] = (char)c;
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456 }
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457 }
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458
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459 if (error_message == NULL)
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460 buffer[iout] = '\0';
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461
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462 else
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463 {
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464 int iin = 0;
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465
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466 buffer[iout++] = ':';
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467 buffer[iout++] = ' ';
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468
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469 while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
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470 buffer[iout++] = error_message[iin++];
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471
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472 /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
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473 buffer[iout] = '\0';
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474 }
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475 }
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476 #endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */
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477
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478 #if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
|
|
479 PNG_FUNCTION(void,PNGAPI
|
|
480 png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message),
|
|
481 PNG_NORETURN)
|
|
482 {
|
|
483 char msg[18+PNG_MAX_ERROR_TEXT];
|
|
484 if (png_ptr == NULL)
|
|
485 png_error(png_ptr, error_message);
|
|
486
|
|
487 else
|
|
488 {
|
|
489 png_format_buffer(png_ptr, msg, error_message);
|
|
490 png_error(png_ptr, msg);
|
|
491 }
|
|
492 }
|
|
493 #endif /* PNG_READ_SUPPORTED && PNG_ERROR_TEXT_SUPPORTED */
|
|
494
|
|
495 #ifdef PNG_WARNINGS_SUPPORTED
|
|
496 void PNGAPI
|
|
497 png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
|
|
498 {
|
|
499 char msg[18+PNG_MAX_ERROR_TEXT];
|
|
500 if (png_ptr == NULL)
|
|
501 png_warning(png_ptr, warning_message);
|
|
502
|
|
503 else
|
|
504 {
|
|
505 png_format_buffer(png_ptr, msg, warning_message);
|
|
506 png_warning(png_ptr, msg);
|
|
507 }
|
|
508 }
|
|
509 #endif /* PNG_WARNINGS_SUPPORTED */
|
|
510
|
|
511 #ifdef PNG_READ_SUPPORTED
|
|
512 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
|
|
513 void PNGAPI
|
|
514 png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
|
|
515 error_message)
|
|
516 {
|
|
517 if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
|
|
518 png_chunk_warning(png_ptr, error_message);
|
|
519
|
|
520 else
|
|
521 png_chunk_error(png_ptr, error_message);
|
|
522
|
|
523 # ifndef PNG_ERROR_TEXT_SUPPORTED
|
|
524 PNG_UNUSED(error_message)
|
|
525 # endif
|
|
526 }
|
|
527 #endif
|
|
528 #endif /* PNG_READ_SUPPORTED */
|
|
529
|
|
530 void /* PRIVATE */
|
|
531 png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
|
|
532 {
|
|
533 # ifndef PNG_WARNINGS_SUPPORTED
|
|
534 PNG_UNUSED(message)
|
|
535 # endif
|
|
536
|
|
537 /* This is always supported, but for just read or just write it
|
|
538 * unconditionally does the right thing.
|
|
539 */
|
|
540 # if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
|
|
541 if (png_ptr->mode & PNG_IS_READ_STRUCT)
|
|
542 # endif
|
|
543
|
|
544 # ifdef PNG_READ_SUPPORTED
|
|
545 {
|
|
546 if (error < PNG_CHUNK_ERROR)
|
|
547 png_chunk_warning(png_ptr, message);
|
|
548
|
|
549 else
|
|
550 png_chunk_benign_error(png_ptr, message);
|
|
551 }
|
|
552 # endif
|
|
553
|
|
554 # if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
|
|
555 else if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
|
|
556 # endif
|
|
557
|
|
558 # ifdef PNG_WRITE_SUPPORTED
|
|
559 {
|
|
560 if (error < PNG_CHUNK_WRITE_ERROR)
|
|
561 png_app_warning(png_ptr, message);
|
|
562
|
|
563 else
|
|
564 png_app_error(png_ptr, message);
|
|
565 }
|
|
566 # endif
|
|
567 }
|
|
568
|
|
569 #ifdef PNG_ERROR_TEXT_SUPPORTED
|
|
570 #ifdef PNG_FLOATING_POINT_SUPPORTED
|
|
571 PNG_FUNCTION(void,
|
|
572 png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
|
|
573 {
|
|
574 # define fixed_message "fixed point overflow in "
|
|
575 # define fixed_message_ln ((sizeof fixed_message)-1)
|
|
576 int iin;
|
|
577 char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
|
|
578 memcpy(msg, fixed_message, fixed_message_ln);
|
|
579 iin = 0;
|
|
580 if (name != NULL) while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
|
|
581 {
|
|
582 msg[fixed_message_ln + iin] = name[iin];
|
|
583 ++iin;
|
|
584 }
|
|
585 msg[fixed_message_ln + iin] = 0;
|
|
586 png_error(png_ptr, msg);
|
|
587 }
|
|
588 #endif
|
|
589 #endif
|
|
590
|
|
591 #ifdef PNG_SETJMP_SUPPORTED
|
|
592 /* This API only exists if ANSI-C style error handling is used,
|
|
593 * otherwise it is necessary for png_default_error to be overridden.
|
|
594 */
|
|
595 jmp_buf* PNGAPI
|
|
596 png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
|
|
597 size_t jmp_buf_size)
|
|
598 {
|
|
599 /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value
|
|
600 * and it must not change after that. Libpng doesn't care how big the
|
|
601 * buffer is, just that it doesn't change.
|
|
602 *
|
|
603 * If the buffer size is no *larger* than the size of jmp_buf when libpng is
|
|
604 * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0
|
|
605 * semantics that this call will not fail. If the size is larger, however,
|
|
606 * the buffer is allocated and this may fail, causing the function to return
|
|
607 * NULL.
|
|
608 */
|
|
609 if (png_ptr == NULL)
|
|
610 return NULL;
|
|
611
|
|
612 if (png_ptr->jmp_buf_ptr == NULL)
|
|
613 {
|
|
614 png_ptr->jmp_buf_size = 0; /* not allocated */
|
|
615
|
|
616 if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))
|
|
617 png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;
|
|
618
|
|
619 else
|
|
620 {
|
|
621 png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *,
|
|
622 png_malloc_warn(png_ptr, jmp_buf_size));
|
|
623
|
|
624 if (png_ptr->jmp_buf_ptr == NULL)
|
|
625 return NULL; /* new NULL return on OOM */
|
|
626
|
|
627 png_ptr->jmp_buf_size = jmp_buf_size;
|
|
628 }
|
|
629 }
|
|
630
|
|
631 else /* Already allocated: check the size */
|
|
632 {
|
|
633 size_t size = png_ptr->jmp_buf_size;
|
|
634
|
|
635 if (size == 0)
|
|
636 {
|
|
637 size = (sizeof png_ptr->jmp_buf_local);
|
|
638 if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)
|
|
639 {
|
|
640 /* This is an internal error in libpng: somehow we have been left
|
|
641 * with a stack allocated jmp_buf when the application regained
|
|
642 * control. It's always possible to fix this up, but for the moment
|
|
643 * this is a png_error because that makes it easy to detect.
|
|
644 */
|
|
645 png_error(png_ptr, "Libpng jmp_buf still allocated");
|
|
646 /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */
|
|
647 }
|
|
648 }
|
|
649
|
|
650 if (size != jmp_buf_size)
|
|
651 {
|
|
652 png_warning(png_ptr, "Application jmp_buf size changed");
|
|
653 return NULL; /* caller will probably crash: no choice here */
|
|
654 }
|
|
655 }
|
|
656
|
|
657 /* Finally fill in the function, now we have a satisfactory buffer. It is
|
|
658 * valid to change the function on every call.
|
|
659 */
|
|
660 png_ptr->longjmp_fn = longjmp_fn;
|
|
661 return png_ptr->jmp_buf_ptr;
|
|
662 }
|
|
663
|
|
664 void /* PRIVATE */
|
|
665 png_free_jmpbuf(png_structrp png_ptr)
|
|
666 {
|
|
667 if (png_ptr != NULL)
|
|
668 {
|
|
669 jmp_buf *jb = png_ptr->jmp_buf_ptr;
|
|
670
|
|
671 /* A size of 0 is used to indicate a local, stack, allocation of the
|
|
672 * pointer; used here and in png.c
|
|
673 */
|
|
674 if (jb != NULL && png_ptr->jmp_buf_size > 0)
|
|
675 {
|
|
676
|
|
677 /* This stuff is so that a failure to free the error control structure
|
|
678 * does not leave libpng in a state with no valid error handling: the
|
|
679 * free always succeeds, if there is an error it gets ignored.
|
|
680 */
|
|
681 if (jb != &png_ptr->jmp_buf_local)
|
|
682 {
|
|
683 /* Make an internal, libpng, jmp_buf to return here */
|
|
684 jmp_buf free_jmp_buf;
|
|
685
|
|
686 if (!setjmp(free_jmp_buf))
|
|
687 {
|
|
688 png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */
|
|
689 png_ptr->jmp_buf_size = 0; /* stack allocation */
|
|
690 png_ptr->longjmp_fn = longjmp;
|
|
691 png_free(png_ptr, jb); /* Return to setjmp on error */
|
|
692 }
|
|
693 }
|
|
694 }
|
|
695
|
|
696 /* *Always* cancel everything out: */
|
|
697 png_ptr->jmp_buf_size = 0;
|
|
698 png_ptr->jmp_buf_ptr = NULL;
|
|
699 png_ptr->longjmp_fn = 0;
|
|
700 }
|
|
701 }
|
|
702 #endif
|
|
703
|
|
704 /* This is the default error handling function. Note that replacements for
|
|
705 * this function MUST NOT RETURN, or the program will likely crash. This
|
|
706 * function is used by default, or if the program supplies NULL for the
|
|
707 * error function pointer in png_set_error_fn().
|
|
708 */
|
|
709 static PNG_FUNCTION(void /* PRIVATE */,
|
|
710 png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),
|
|
711 PNG_NORETURN)
|
|
712 {
|
|
713 #ifdef PNG_CONSOLE_IO_SUPPORTED
|
|
714 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
|
|
715 /* Check on NULL only added in 1.5.4 */
|
|
716 if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
|
|
717 {
|
|
718 /* Strip "#nnnn " from beginning of error message. */
|
|
719 int offset;
|
|
720 char error_number[16];
|
|
721 for (offset = 0; offset<15; offset++)
|
|
722 {
|
|
723 error_number[offset] = error_message[offset + 1];
|
|
724 if (error_message[offset] == ' ')
|
|
725 break;
|
|
726 }
|
|
727
|
|
728 if ((offset > 1) && (offset < 15))
|
|
729 {
|
|
730 error_number[offset - 1] = '\0';
|
|
731 fprintf(stderr, "libpng error no. %s: %s",
|
|
732 error_number, error_message + offset + 1);
|
|
733 fprintf(stderr, PNG_STRING_NEWLINE);
|
|
734 }
|
|
735
|
|
736 else
|
|
737 {
|
|
738 fprintf(stderr, "libpng error: %s, offset=%d",
|
|
739 error_message, offset);
|
|
740 fprintf(stderr, PNG_STRING_NEWLINE);
|
|
741 }
|
|
742 }
|
|
743 else
|
|
744 #endif
|
|
745 {
|
|
746 fprintf(stderr, "libpng error: %s", error_message ? error_message :
|
|
747 "undefined");
|
|
748 fprintf(stderr, PNG_STRING_NEWLINE);
|
|
749 }
|
|
750 #else
|
|
751 PNG_UNUSED(error_message) /* Make compiler happy */
|
|
752 #endif
|
|
753 png_longjmp(png_ptr, 1);
|
|
754 }
|
|
755
|
|
756 PNG_FUNCTION(void,PNGAPI
|
|
757 png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)
|
|
758 {
|
|
759 #ifdef PNG_SETJMP_SUPPORTED
|
|
760 if (png_ptr && png_ptr->longjmp_fn && png_ptr->jmp_buf_ptr)
|
|
761 png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
|
|
762 #endif
|
|
763
|
|
764 /* If control reaches this point, png_longjmp() must not return. The only
|
|
765 * choice is to terminate the whole process (or maybe the thread); to do
|
|
766 * this the ANSI-C abort() function is used unless a different method is
|
|
767 * implemented by overriding the default configuration setting for
|
|
768 * PNG_ABORT().
|
|
769 */
|
|
770 PNG_ABORT();
|
|
771 }
|
|
772
|
|
773 #ifdef PNG_WARNINGS_SUPPORTED
|
|
774 /* This function is called when there is a warning, but the library thinks
|
|
775 * it can continue anyway. Replacement functions don't have to do anything
|
|
776 * here if you don't want them to. In the default configuration, png_ptr is
|
|
777 * not used, but it is passed in case it may be useful.
|
|
778 */
|
|
779 static void /* PRIVATE */
|
|
780 png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
|
|
781 {
|
|
782 #ifdef PNG_CONSOLE_IO_SUPPORTED
|
|
783 # ifdef PNG_ERROR_NUMBERS_SUPPORTED
|
|
784 if (*warning_message == PNG_LITERAL_SHARP)
|
|
785 {
|
|
786 int offset;
|
|
787 char warning_number[16];
|
|
788 for (offset = 0; offset < 15; offset++)
|
|
789 {
|
|
790 warning_number[offset] = warning_message[offset + 1];
|
|
791 if (warning_message[offset] == ' ')
|
|
792 break;
|
|
793 }
|
|
794
|
|
795 if ((offset > 1) && (offset < 15))
|
|
796 {
|
|
797 warning_number[offset + 1] = '\0';
|
|
798 fprintf(stderr, "libpng warning no. %s: %s",
|
|
799 warning_number, warning_message + offset);
|
|
800 fprintf(stderr, PNG_STRING_NEWLINE);
|
|
801 }
|
|
802
|
|
803 else
|
|
804 {
|
|
805 fprintf(stderr, "libpng warning: %s",
|
|
806 warning_message);
|
|
807 fprintf(stderr, PNG_STRING_NEWLINE);
|
|
808 }
|
|
809 }
|
|
810 else
|
|
811 # endif
|
|
812
|
|
813 {
|
|
814 fprintf(stderr, "libpng warning: %s", warning_message);
|
|
815 fprintf(stderr, PNG_STRING_NEWLINE);
|
|
816 }
|
|
817 #else
|
|
818 PNG_UNUSED(warning_message) /* Make compiler happy */
|
|
819 #endif
|
|
820 PNG_UNUSED(png_ptr) /* Make compiler happy */
|
|
821 }
|
|
822 #endif /* PNG_WARNINGS_SUPPORTED */
|
|
823
|
|
824 /* This function is called when the application wants to use another method
|
|
825 * of handling errors and warnings. Note that the error function MUST NOT
|
|
826 * return to the calling routine or serious problems will occur. The return
|
|
827 * method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1)
|
|
828 */
|
|
829 void PNGAPI
|
|
830 png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr,
|
|
831 png_error_ptr error_fn, png_error_ptr warning_fn)
|
|
832 {
|
|
833 if (png_ptr == NULL)
|
|
834 return;
|
|
835
|
|
836 png_ptr->error_ptr = error_ptr;
|
|
837 png_ptr->error_fn = error_fn;
|
|
838 #ifdef PNG_WARNINGS_SUPPORTED
|
|
839 png_ptr->warning_fn = warning_fn;
|
|
840 #else
|
|
841 PNG_UNUSED(warning_fn)
|
|
842 #endif
|
|
843 }
|
|
844
|
|
845
|
|
846 /* This function returns a pointer to the error_ptr associated with the user
|
|
847 * functions. The application should free any memory associated with this
|
|
848 * pointer before png_write_destroy and png_read_destroy are called.
|
|
849 */
|
|
850 png_voidp PNGAPI
|
|
851 png_get_error_ptr(png_const_structrp png_ptr)
|
|
852 {
|
|
853 if (png_ptr == NULL)
|
|
854 return NULL;
|
|
855
|
|
856 return ((png_voidp)png_ptr->error_ptr);
|
|
857 }
|
|
858
|
|
859
|
|
860 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
|
|
861 void PNGAPI
|
|
862 png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
|
|
863 {
|
|
864 if (png_ptr != NULL)
|
|
865 {
|
|
866 png_ptr->flags &=
|
|
867 ((~(PNG_FLAG_STRIP_ERROR_NUMBERS |
|
|
868 PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
|
|
869 }
|
|
870 }
|
|
871 #endif
|
|
872
|
|
873 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
|
|
874 defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
|
|
875 /* Currently the above both depend on SETJMP_SUPPORTED, however it would be
|
|
876 * possible to implement without setjmp support just so long as there is some
|
|
877 * way to handle the error return here:
|
|
878 */
|
|
879 PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI
|
|
880 png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message),
|
|
881 PNG_NORETURN)
|
|
882 {
|
|
883 const png_const_structrp png_ptr = png_nonconst_ptr;
|
|
884 png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
|
|
885
|
|
886 /* An error is always logged here, overwriting anything (typically a warning)
|
|
887 * that is already there:
|
|
888 */
|
|
889 if (image != NULL)
|
|
890 {
|
|
891 png_safecat(image->message, (sizeof image->message), 0, error_message);
|
|
892 image->warning_or_error |= PNG_IMAGE_ERROR;
|
|
893
|
|
894 /* Retrieve the jmp_buf from within the png_control, making this work for
|
|
895 * C++ compilation too is pretty tricky: C++ wants a pointer to the first
|
|
896 * element of a jmp_buf, but C doesn't tell us the type of that.
|
|
897 */
|
|
898 if (image->opaque != NULL && image->opaque->error_buf != NULL)
|
|
899 longjmp(png_control_jmp_buf(image->opaque), 1);
|
|
900
|
|
901 /* Missing longjmp buffer, the following is to help debugging: */
|
|
902 {
|
|
903 size_t pos = png_safecat(image->message, (sizeof image->message), 0,
|
|
904 "bad longjmp: ");
|
|
905 png_safecat(image->message, (sizeof image->message), pos,
|
|
906 error_message);
|
|
907 }
|
|
908 }
|
|
909
|
|
910 /* Here on an internal programming error. */
|
|
911 abort();
|
|
912 }
|
|
913
|
|
914 #ifdef PNG_WARNINGS_SUPPORTED
|
|
915 void /* PRIVATE */ PNGCBAPI
|
|
916 png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
|
|
917 {
|
|
918 const png_const_structrp png_ptr = png_nonconst_ptr;
|
|
919 png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
|
|
920
|
|
921 /* A warning is only logged if there is no prior warning or error. */
|
|
922 if (image->warning_or_error == 0)
|
|
923 {
|
|
924 png_safecat(image->message, (sizeof image->message), 0, warning_message);
|
|
925 image->warning_or_error |= PNG_IMAGE_WARNING;
|
|
926 }
|
|
927 }
|
|
928 #endif
|
|
929
|
|
930 int /* PRIVATE */
|
|
931 png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
|
|
932 {
|
|
933 volatile png_imagep image = image_in;
|
|
934 volatile int result;
|
|
935 volatile png_voidp saved_error_buf;
|
|
936 jmp_buf safe_jmpbuf;
|
|
937
|
|
938 /* Safely execute function(arg) with png_error returning to this function. */
|
|
939 saved_error_buf = image->opaque->error_buf;
|
|
940 result = setjmp(safe_jmpbuf) == 0;
|
|
941
|
|
942 if (result)
|
|
943 {
|
|
944
|
|
945 image->opaque->error_buf = safe_jmpbuf;
|
|
946 result = function(arg);
|
|
947 }
|
|
948
|
|
949 image->opaque->error_buf = saved_error_buf;
|
|
950
|
|
951 /* And do the cleanup prior to any failure return. */
|
|
952 if (!result)
|
|
953 png_image_free(image);
|
|
954
|
|
955 return result;
|
|
956 }
|
|
957 #endif /* SIMPLIFIED READ/WRITE */
|
|
958 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
|