wp/wp-includes/compat.php
changeset 7 cf61fcea0001
parent 5 5e2f62d02dcd
child 9 177826044cd9
equal deleted inserted replaced
6:490d5cc509ed 7:cf61fcea0001
    18  *
    18  *
    19  * @ignore
    19  * @ignore
    20  * @since 4.2.2
    20  * @since 4.2.2
    21  * @access private
    21  * @access private
    22  *
    22  *
       
    23  * @staticvar string $utf8_pcre
       
    24  *
    23  * @param bool $set - Used for testing only
    25  * @param bool $set - Used for testing only
    24  *             null   : default - get PCRE/u capability
    26  *             null   : default - get PCRE/u capability
    25  *             false  : Used for testing - return false for future calls to this function
    27  *             false  : Used for testing - return false for future calls to this function
    26  *             'reset': Used for testing - restore default behavior of this function
    28  *             'reset': Used for testing - restore default behavior of this function
    27  */
    29  */
    38 
    40 
    39 	return $utf8_pcre;
    41 	return $utf8_pcre;
    40 }
    42 }
    41 
    43 
    42 if ( ! function_exists( 'mb_substr' ) ) :
    44 if ( ! function_exists( 'mb_substr' ) ) :
       
    45 	/**
       
    46 	 * Compat function to mimic mb_substr().
       
    47 	 *
       
    48 	 * @ignore
       
    49 	 * @since 3.2.0
       
    50 	 *
       
    51 	 * @see _mb_substr()
       
    52 	 *
       
    53 	 * @param string      $str      The string to extract the substring from.
       
    54 	 * @param int         $start    Position to being extraction from in `$str`.
       
    55 	 * @param int|null    $length   Optional. Maximum number of characters to extract from `$str`.
       
    56 	 *                              Default null.
       
    57 	 * @param string|null $encoding Optional. Character encoding to use. Default null.
       
    58 	 * @return string Extracted substring.
       
    59 	 */
    43 	function mb_substr( $str, $start, $length = null, $encoding = null ) {
    60 	function mb_substr( $str, $start, $length = null, $encoding = null ) {
    44 		return _mb_substr( $str, $start, $length, $encoding );
    61 		return _mb_substr( $str, $start, $length, $encoding );
    45 	}
    62 	}
    46 endif;
    63 endif;
    47 
    64 
    48 /*
    65 /**
       
    66  * Internal compat function to mimic mb_substr().
       
    67  *
    49  * Only understands UTF-8 and 8bit.  All other character sets will be treated as 8bit.
    68  * Only understands UTF-8 and 8bit.  All other character sets will be treated as 8bit.
    50  * For $encoding === UTF-8, the $str input is expected to be a valid UTF-8 byte sequence.
    69  * For $encoding === UTF-8, the $str input is expected to be a valid UTF-8 byte sequence.
    51  * The behavior of this function for invalid inputs is undefined.
    70  * The behavior of this function for invalid inputs is undefined.
       
    71  *
       
    72  * @ignore
       
    73  * @since 3.2.0
       
    74  *
       
    75  * @param string      $str      The string to extract the substring from.
       
    76  * @param int         $start    Position to being extraction from in `$str`.
       
    77  * @param int|null    $length   Optional. Maximum number of characters to extract from `$str`.
       
    78  *                              Default null.
       
    79  * @param string|null $encoding Optional. Character encoding to use. Default null.
       
    80  * @return string Extracted substring.
    52  */
    81  */
    53 function _mb_substr( $str, $start, $length = null, $encoding = null ) {
    82 function _mb_substr( $str, $start, $length = null, $encoding = null ) {
    54 	if ( null === $encoding ) {
    83 	if ( null === $encoding ) {
    55 		$encoding = get_option( 'blog_charset' );
    84 		$encoding = get_option( 'blog_charset' );
    56 	}
    85 	}
    57 
    86 
    58 	// The solution below works only for UTF-8,
    87 	/*
    59 	// so in case of a different charset just use built-in substr()
    88 	 * The solution below works only for UTF-8, so in case of a different
       
    89 	 * charset just use built-in substr().
       
    90 	 */
    60 	if ( ! in_array( $encoding, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ) ) ) {
    91 	if ( ! in_array( $encoding, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ) ) ) {
    61 		return is_null( $length ) ? substr( $str, $start ) : substr( $str, $start, $length );
    92 		return is_null( $length ) ? substr( $str, $start ) : substr( $str, $start, $length );
    62 	}
    93 	}
    63 
    94 
    64 	if ( _wp_can_use_pcre_u() ) {
    95 	if ( _wp_can_use_pcre_u() ) {
    65 		// Use the regex unicode support to separate the UTF-8 characters into an array
    96 		// Use the regex unicode support to separate the UTF-8 characters into an array.
    66 		preg_match_all( '/./us', $str, $match );
    97 		preg_match_all( '/./us', $str, $match );
    67 		$chars = is_null( $length ) ? array_slice( $match[0], $start ) : array_slice( $match[0], $start, $length );
    98 		$chars = is_null( $length ) ? array_slice( $match[0], $start ) : array_slice( $match[0], $start, $length );
    68 		return implode( '', $chars );
    99 		return implode( '', $chars );
    69 	}
   100 	}
    70 
   101 
    78 		| \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences   11110xxx 10xxxxxx * 3
   109 		| \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences   11110xxx 10xxxxxx * 3
    79 		| [\xF1-\xF3][\x80-\xBF]{3}
   110 		| [\xF1-\xF3][\x80-\xBF]{3}
    80 		| \xF4[\x80-\x8F][\x80-\xBF]{2}
   111 		| \xF4[\x80-\x8F][\x80-\xBF]{2}
    81 	)/x';
   112 	)/x';
    82 
   113 
    83 	$chars = array( '' ); // Start with 1 element instead of 0 since the first thing we do is pop
   114 	// Start with 1 element instead of 0 since the first thing we do is pop.
       
   115 	$chars = array( '' );
    84 	do {
   116 	do {
    85 		// We had some string left over from the last round, but we counted it in that last round.
   117 		// We had some string left over from the last round, but we counted it in that last round.
    86 		array_pop( $chars );
   118 		array_pop( $chars );
    87 
   119 
    88 		// Split by UTF-8 character, limit to 1000 characters (last array element will contain the rest of the string)
   120 		/*
       
   121 		 * Split by UTF-8 character, limit to 1000 characters (last array element will contain
       
   122 		 * the rest of the string).
       
   123 		 */
    89 		$pieces = preg_split( $regex, $str, 1000, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );
   124 		$pieces = preg_split( $regex, $str, 1000, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );
    90 
   125 
    91 		$chars = array_merge( $chars, $pieces );
   126 		$chars = array_merge( $chars, $pieces );
    92 	} while ( count( $pieces ) > 1 && $str = array_pop( $pieces ) ); // If there's anything left over, repeat the loop.
   127 
       
   128 	// If there's anything left over, repeat the loop.
       
   129 	} while ( count( $pieces ) > 1 && $str = array_pop( $pieces ) );
    93 
   130 
    94 	return join( '', array_slice( $chars, $start, $length ) );
   131 	return join( '', array_slice( $chars, $start, $length ) );
    95 }
   132 }
    96 
   133 
    97 if ( ! function_exists( 'mb_strlen' ) ) :
   134 if ( ! function_exists( 'mb_strlen' ) ) :
       
   135 	/**
       
   136 	 * Compat function to mimic mb_strlen().
       
   137 	 *
       
   138 	 * @ignore
       
   139 	 * @since 4.2.0
       
   140 	 *
       
   141 	 * @see _mb_strlen()
       
   142 	 *
       
   143 	 * @param string      $str      The string to retrieve the character length from.
       
   144 	 * @param string|null $encoding Optional. Character encoding to use. Default null.
       
   145 	 * @return int String length of `$str`.
       
   146 	 */
    98 	function mb_strlen( $str, $encoding = null ) {
   147 	function mb_strlen( $str, $encoding = null ) {
    99 		return _mb_strlen( $str, $encoding );
   148 		return _mb_strlen( $str, $encoding );
   100 	}
   149 	}
   101 endif;
   150 endif;
   102 
   151 
   103 /*
   152 /**
       
   153  * Internal compat function to mimic mb_strlen().
       
   154  *
   104  * Only understands UTF-8 and 8bit.  All other character sets will be treated as 8bit.
   155  * Only understands UTF-8 and 8bit.  All other character sets will be treated as 8bit.
   105  * For $encoding === UTF-8, the $str input is expected to be a valid UTF-8 byte sequence.
   156  * For $encoding === UTF-8, the `$str` input is expected to be a valid UTF-8 byte
   106  * The behavior of this function for invalid inputs is undefined.
   157  * sequence. The behavior of this function for invalid inputs is undefined.
       
   158  *
       
   159  * @ignore
       
   160  * @since 4.2.0
       
   161  *
       
   162  * @param string      $str      The string to retrieve the character length from.
       
   163  * @param string|null $encoding Optional. Character encoding to use. Default null.
       
   164  * @return int String length of `$str`.
   107  */
   165  */
   108 function _mb_strlen( $str, $encoding = null ) {
   166 function _mb_strlen( $str, $encoding = null ) {
   109 	if ( null === $encoding ) {
   167 	if ( null === $encoding ) {
   110 		$encoding = get_option( 'blog_charset' );
   168 		$encoding = get_option( 'blog_charset' );
   111 	}
   169 	}
   112 
   170 
   113 	// The solution below works only for UTF-8,
   171 	/*
   114 	// so in case of a different charset just use built-in strlen()
   172 	 * The solution below works only for UTF-8, so in case of a different charset
       
   173 	 * just use built-in strlen().
       
   174 	 */
   115 	if ( ! in_array( $encoding, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ) ) ) {
   175 	if ( ! in_array( $encoding, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ) ) ) {
   116 		return strlen( $str );
   176 		return strlen( $str );
   117 	}
   177 	}
   118 
   178 
   119 	if ( _wp_can_use_pcre_u() ) {
   179 	if ( _wp_can_use_pcre_u() ) {
   120 		// Use the regex unicode support to separate the UTF-8 characters into an array
   180 		// Use the regex unicode support to separate the UTF-8 characters into an array.
   121 		preg_match_all( '/./us', $str, $match );
   181 		preg_match_all( '/./us', $str, $match );
   122 		return count( $match[0] );
   182 		return count( $match[0] );
   123 	}
   183 	}
   124 
   184 
   125 	$regex = '/(?:
   185 	$regex = '/(?:
   132 		| \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences   11110xxx 10xxxxxx * 3
   192 		| \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences   11110xxx 10xxxxxx * 3
   133 		| [\xF1-\xF3][\x80-\xBF]{3}
   193 		| [\xF1-\xF3][\x80-\xBF]{3}
   134 		| \xF4[\x80-\x8F][\x80-\xBF]{2}
   194 		| \xF4[\x80-\x8F][\x80-\xBF]{2}
   135 	)/x';
   195 	)/x';
   136 
   196 
   137 	$count = 1; // Start at 1 instead of 0 since the first thing we do is decrement
   197 	// Start at 1 instead of 0 since the first thing we do is decrement.
       
   198 	$count = 1;
   138 	do {
   199 	do {
   139 		// We had some string left over from the last round, but we counted it in that last round.
   200 		// We had some string left over from the last round, but we counted it in that last round.
   140 		$count--;
   201 		$count--;
   141 
   202 
   142 		// Split by UTF-8 character, limit to 1000 characters (last array element will contain the rest of the string)
   203 		/*
       
   204 		 * Split by UTF-8 character, limit to 1000 characters (last array element will contain
       
   205 		 * the rest of the string).
       
   206 		 */
   143 		$pieces = preg_split( $regex, $str, 1000 );
   207 		$pieces = preg_split( $regex, $str, 1000 );
   144 
   208 
   145 		// Increment
   209 		// Increment.
   146 		$count += count( $pieces );
   210 		$count += count( $pieces );
   147 	} while ( $str = array_pop( $pieces ) ); // If there's anything left over, repeat the loop.
   211 
   148 
   212 	// If there's anything left over, repeat the loop.
   149 	// Fencepost: preg_split() always returns one extra item in the array
   213 	} while ( $str = array_pop( $pieces ) );
       
   214 
       
   215 	// Fencepost: preg_split() always returns one extra item in the array.
   150 	return --$count;
   216 	return --$count;
   151 }
   217 }
   152 
   218 
   153 if ( !function_exists('hash_hmac') ):
   219 if ( !function_exists('hash_hmac') ):
       
   220 /**
       
   221  * Compat function to mimic hash_hmac().
       
   222  *
       
   223  * @ignore
       
   224  * @since 3.2.0
       
   225  *
       
   226  * @see _hash_hmac()
       
   227  *
       
   228  * @param string $algo       Hash algorithm. Accepts 'md5' or 'sha1'.
       
   229  * @param string $data       Data to be hashed.
       
   230  * @param string $key        Secret key to use for generating the hash.
       
   231  * @param bool   $raw_output Optional. Whether to output raw binary data (true),
       
   232  *                           or lowercase hexits (false). Default false.
       
   233  * @return string|false The hash in output determined by `$raw_output`. False if `$algo`
       
   234  *                      is unknown or invalid.
       
   235  */
   154 function hash_hmac($algo, $data, $key, $raw_output = false) {
   236 function hash_hmac($algo, $data, $key, $raw_output = false) {
   155 	return _hash_hmac($algo, $data, $key, $raw_output);
   237 	return _hash_hmac($algo, $data, $key, $raw_output);
   156 }
   238 }
   157 endif;
   239 endif;
   158 
   240 
       
   241 /**
       
   242  * Internal compat function to mimic hash_hmac().
       
   243  *
       
   244  * @ignore
       
   245  * @since 3.2.0
       
   246  *
       
   247  * @param string $algo       Hash algorithm. Accepts 'md5' or 'sha1'.
       
   248  * @param string $data       Data to be hashed.
       
   249  * @param string $key        Secret key to use for generating the hash.
       
   250  * @param bool   $raw_output Optional. Whether to output raw binary data (true),
       
   251  *                           or lowercase hexits (false). Default false.
       
   252  * @return string|false The hash in output determined by `$raw_output`. False if `$algo`
       
   253  *                      is unknown or invalid.
       
   254  */
   159 function _hash_hmac($algo, $data, $key, $raw_output = false) {
   255 function _hash_hmac($algo, $data, $key, $raw_output = false) {
   160 	$packs = array('md5' => 'H32', 'sha1' => 'H40');
   256 	$packs = array('md5' => 'H32', 'sha1' => 'H40');
   161 
   257 
   162 	if ( !isset($packs[$algo]) )
   258 	if ( !isset($packs[$algo]) )
   163 		return false;
   259 		return false;
   191 		return $wp_json->encodeUnsafe( $string );
   287 		return $wp_json->encodeUnsafe( $string );
   192 	}
   288 	}
   193 }
   289 }
   194 
   290 
   195 if ( !function_exists('json_decode') ) {
   291 if ( !function_exists('json_decode') ) {
       
   292 	/**
       
   293 	 * @global Services_JSON $wp_json
       
   294 	 * @param string $string
       
   295 	 * @param bool   $assoc_array
       
   296 	 * @return object|array
       
   297 	 */
   196 	function json_decode( $string, $assoc_array = false ) {
   298 	function json_decode( $string, $assoc_array = false ) {
   197 		global $wp_json;
   299 		global $wp_json;
   198 
   300 
   199 		if ( ! ($wp_json instanceof Services_JSON ) ) {
   301 		if ( ! ($wp_json instanceof Services_JSON ) ) {
   200 			require_once( ABSPATH . WPINC . '/class-json.php' );
   302 			require_once( ABSPATH . WPINC . '/class-json.php' );
   204 		$res = $wp_json->decode( $string );
   306 		$res = $wp_json->decode( $string );
   205 		if ( $assoc_array )
   307 		if ( $assoc_array )
   206 			$res = _json_decode_object_helper( $res );
   308 			$res = _json_decode_object_helper( $res );
   207 		return $res;
   309 		return $res;
   208 	}
   310 	}
       
   311 
       
   312 	/**
       
   313 	 * @param object $data
       
   314 	 * @return array
       
   315 	 */
   209 	function _json_decode_object_helper($data) {
   316 	function _json_decode_object_helper($data) {
   210 		if ( is_object($data) )
   317 		if ( is_object($data) )
   211 			$data = get_object_vars($data);
   318 			$data = get_object_vars($data);
   212 		return is_array($data) ? array_map(__FUNCTION__, $data) : $data;
   319 		return is_array($data) ? array_map(__FUNCTION__, $data) : $data;
   213 	}
   320 	}
   214 }
   321 }
   215 
   322 
   216 if ( ! function_exists( 'hash_equals' ) ) :
   323 if ( ! function_exists( 'hash_equals' ) ) :
   217 /**
   324 /**
   218  * Compare two strings in constant time.
   325  * Timing attack safe string comparison
       
   326  *
       
   327  * Compares two strings using the same time whether they're equal or not.
   219  *
   328  *
   220  * This function was added in PHP 5.6.
   329  * This function was added in PHP 5.6.
   221  * It can leak the length of a string.
   330  *
       
   331  * Note: It can leak the length of a string when arguments of differing length are supplied.
   222  *
   332  *
   223  * @since 3.9.2
   333  * @since 3.9.2
   224  *
   334  *
   225  * @param string $a Expected string.
   335  * @param string $a Expected string.
   226  * @param string $b Actual string.
   336  * @param string $b Actual, user supplied, string.
   227  * @return bool Whether strings are equal.
   337  * @return bool Whether strings are equal.
   228  */
   338  */
   229 function hash_equals( $a, $b ) {
   339 function hash_equals( $a, $b ) {
   230 	$a_length = strlen( $a );
   340 	$a_length = strlen( $a );
   231 	if ( $a_length !== strlen( $b ) ) {
   341 	if ( $a_length !== strlen( $b ) ) {
   245 // JSON_PRETTY_PRINT was introduced in PHP 5.4
   355 // JSON_PRETTY_PRINT was introduced in PHP 5.4
   246 // Defined here to prevent a notice when using it with wp_json_encode()
   356 // Defined here to prevent a notice when using it with wp_json_encode()
   247 if ( ! defined( 'JSON_PRETTY_PRINT' ) ) {
   357 if ( ! defined( 'JSON_PRETTY_PRINT' ) ) {
   248 	define( 'JSON_PRETTY_PRINT', 128 );
   358 	define( 'JSON_PRETTY_PRINT', 128 );
   249 }
   359 }
       
   360 
       
   361 if ( ! function_exists( 'json_last_error_msg' ) ) :
       
   362 	/**
       
   363 	 * Retrieves the error string of the last json_encode() or json_decode() call.
       
   364 	 *
       
   365 	 * @since 4.4.0
       
   366 	 *
       
   367 	 * @internal This is a compatibility function for PHP <5.5
       
   368 	 *
       
   369 	 * @return bool|string Returns the error message on success, "No Error" if no error has occurred,
       
   370 	 *                     or false on failure.
       
   371 	 */
       
   372 	function json_last_error_msg() {
       
   373 		// See https://core.trac.wordpress.org/ticket/27799.
       
   374 		if ( ! function_exists( 'json_last_error' ) ) {
       
   375 			return false;
       
   376 		}
       
   377 
       
   378 		$last_error_code = json_last_error();
       
   379 
       
   380 		// Just in case JSON_ERROR_NONE is not defined.
       
   381 		$error_code_none = defined( 'JSON_ERROR_NONE' ) ? JSON_ERROR_NONE : 0;
       
   382 
       
   383 		switch ( true ) {
       
   384 			case $last_error_code === $error_code_none:
       
   385 				return 'No error';
       
   386 
       
   387 			case defined( 'JSON_ERROR_DEPTH' ) && JSON_ERROR_DEPTH === $last_error_code:
       
   388 				return 'Maximum stack depth exceeded';
       
   389 
       
   390 			case defined( 'JSON_ERROR_STATE_MISMATCH' ) && JSON_ERROR_STATE_MISMATCH === $last_error_code:
       
   391 				return 'State mismatch (invalid or malformed JSON)';
       
   392 
       
   393 			case defined( 'JSON_ERROR_CTRL_CHAR' ) && JSON_ERROR_CTRL_CHAR === $last_error_code:
       
   394 				return 'Control character error, possibly incorrectly encoded';
       
   395 
       
   396 			case defined( 'JSON_ERROR_SYNTAX' ) && JSON_ERROR_SYNTAX === $last_error_code:
       
   397 				return 'Syntax error';
       
   398 
       
   399 			case defined( 'JSON_ERROR_UTF8' ) && JSON_ERROR_UTF8 === $last_error_code:
       
   400 				return 'Malformed UTF-8 characters, possibly incorrectly encoded';
       
   401 
       
   402 			case defined( 'JSON_ERROR_RECURSION' ) && JSON_ERROR_RECURSION === $last_error_code:
       
   403 				return 'Recursion detected';
       
   404 
       
   405 			case defined( 'JSON_ERROR_INF_OR_NAN' ) && JSON_ERROR_INF_OR_NAN === $last_error_code:
       
   406 				return 'Inf and NaN cannot be JSON encoded';
       
   407 
       
   408 			case defined( 'JSON_ERROR_UNSUPPORTED_TYPE' ) && JSON_ERROR_UNSUPPORTED_TYPE === $last_error_code:
       
   409 				return 'Type is not supported';
       
   410 
       
   411 			default:
       
   412 				return 'An unknown error occurred';
       
   413 		}
       
   414 	}
       
   415 endif;
       
   416 
       
   417 if ( ! interface_exists( 'JsonSerializable' ) ) {
       
   418 	define( 'WP_JSON_SERIALIZE_COMPATIBLE', true );
       
   419 	/**
       
   420 	 * JsonSerializable interface.
       
   421 	 *
       
   422 	 * Compatibility shim for PHP <5.4
       
   423 	 *
       
   424 	 * @link https://secure.php.net/jsonserializable
       
   425 	 *
       
   426 	 * @since 4.4.0
       
   427 	 */
       
   428 	interface JsonSerializable {
       
   429 		public function jsonSerialize();
       
   430 	}
       
   431 }
       
   432 
       
   433 // random_int was introduced in PHP 7.0
       
   434 if ( ! function_exists( 'random_int' ) ) {
       
   435 	require ABSPATH . WPINC . '/random_compat/random.php';
       
   436 }
       
   437 
       
   438 if ( ! function_exists( 'array_replace_recursive' ) ) :
       
   439 	/**
       
   440 	 * PHP-agnostic version of {@link array_replace_recursive()}.
       
   441 	 *
       
   442 	 * The array_replace_recursive() function is a PHP 5.3 function. WordPress
       
   443 	 * currently supports down to PHP 5.2, so this method is a workaround
       
   444 	 * for PHP 5.2.
       
   445 	 *
       
   446 	 * Note: array_replace_recursive() supports infinite arguments, but for our use-
       
   447 	 * case, we only need to support two arguments.
       
   448 	 *
       
   449 	 * Subject to removal once WordPress makes PHP 5.3.0 the minimum requirement.
       
   450 	 *
       
   451 	 * @since 4.5.3
       
   452 	 *
       
   453 	 * @see https://secure.php.net/manual/en/function.array-replace-recursive.php#109390
       
   454 	 *
       
   455 	 * @param  array $base         Array with keys needing to be replaced.
       
   456 	 * @param  array $replacements Array with the replaced keys.
       
   457 	 *
       
   458 	 * @return array
       
   459 	 */
       
   460 	function array_replace_recursive( $base = array(), $replacements = array() ) {
       
   461 		foreach ( array_slice( func_get_args(), 1 ) as $replacements ) {
       
   462 			$bref_stack = array( &$base );
       
   463 			$head_stack = array( $replacements );
       
   464 
       
   465 			do {
       
   466 				end( $bref_stack );
       
   467 
       
   468 				$bref = &$bref_stack[ key( $bref_stack ) ];
       
   469 				$head = array_pop( $head_stack );
       
   470 
       
   471 				unset( $bref_stack[ key( $bref_stack ) ] );
       
   472 
       
   473 				foreach ( array_keys( $head ) as $key ) {
       
   474 					if ( isset( $key, $bref ) &&
       
   475 					     isset( $bref[ $key ] ) && is_array( $bref[ $key ] ) &&
       
   476 					     isset( $head[ $key ] ) && is_array( $head[ $key ] )
       
   477 					) {
       
   478 						$bref_stack[] = &$bref[ $key ];
       
   479 						$head_stack[] = $head[ $key ];
       
   480 					} else {
       
   481 						$bref[ $key ] = $head[ $key ];
       
   482 					}
       
   483 				}
       
   484 			} while ( count( $head_stack ) );
       
   485 		}
       
   486 
       
   487 		return $base;
       
   488 	}
       
   489 endif;
       
   490 
       
   491 /**
       
   492  * Polyfill for the SPL autoloader. In PHP 5.2 (but not 5.3 and later), SPL can
       
   493  * be disabled, and PHP 7.2 raises notices if the compiler finds an __autoload()
       
   494  * function declaration. Function availability is checked here, and the
       
   495  * autoloader is included only if necessary.
       
   496  */
       
   497 if ( ! function_exists( 'spl_autoload_register' ) ) {
       
   498 	require_once ABSPATH . WPINC . '/spl-autoload-compat.php';
       
   499 }
       
   500 
       
   501 if ( ! function_exists( 'is_countable' ) ) {
       
   502 	/**
       
   503 	 * Polyfill for is_countable() function added in PHP 7.3.
       
   504 	 *
       
   505 	 * Verify that the content of a variable is an array or an object
       
   506 	 * implementing the Countable interface.
       
   507 	 *
       
   508 	 * @since 4.9.6
       
   509 	 *
       
   510 	 * @param mixed $var The value to check.
       
   511 	 *
       
   512 	 * @return bool True if `$var` is countable, false otherwise.
       
   513 	 */
       
   514 	function is_countable( $var ) {
       
   515 		return ( is_array( $var )
       
   516 			|| $var instanceof Countable
       
   517 			|| $var instanceof SimpleXMLElement
       
   518 			|| $var instanceof ResourceBundle
       
   519 		);
       
   520 	}
       
   521 }
       
   522 
       
   523 if ( ! function_exists( 'is_iterable' ) ) {
       
   524 	/**
       
   525 	 * Polyfill for is_iterable() function added in PHP 7.1.
       
   526 	 *
       
   527 	 * Verify that the content of a variable is an array or an object
       
   528 	 * implementing the Traversable interface.
       
   529 	 *
       
   530 	 * @since 4.9.6
       
   531 	 *
       
   532 	 * @param mixed $var The value to check.
       
   533 	 *
       
   534 	 * @return bool True if `$var` is iterable, false otherwise.
       
   535 	 */
       
   536 	function is_iterable( $var ) {
       
   537 		return ( is_array( $var ) || $var instanceof Traversable );
       
   538 	}
       
   539 }