PHP JSON_encode（）收到“格式错误的UTF-8字符，可能编码错误”（错误）

Question

I cannot solve this issue and I'm getting crazy.

JSON_encode() is casting the error: Malformed UTF-8 characters, possibly incorrectly encoded on few records (2 or 3) from a set of 10k records. However this seems very impossible to fix.

• mysql is already utf8mb4 everywhere (database, table, columns and collation)
• php is 7.2 and of course in utf8
• apache default charset is utf8 (however the error is throw at PHP-level).

I can also print to screen correctly the record in PHP without issue in a simple HTML debug page. However If I try to encode it in JSON I get the error.

I found that these records have been imported from a CVS probably bypassing the cleaner. What is so strange is that the entire CSV file is parsed with:

$this->encoding = mb_detect_encoding($source,mb_detect_order(),true);
if ($this->encoding!="" && $this->encoding!="UTF8") {
    $source = iconv($this->encoding, "UTF-8", $source);
} 

I cannot post any full broken data due to the privacy (and GDPR). However I succeed to extract a part which seems to be the broken one:

RESIDENCE �PRINCIPE

UPDATES

I try to get the bitcode of these broken chars. This is what I found. In ASCII by using simple native function str_split and ord these char is:

'�' 160

I would like to find the bitcode also in utf8, so I find this usefull function on PHP.net http://php.net/manual/en/function.ord.php#109812 Which try to find bitcode of MultiByteStrings. and it gives me:

-2096

Which is....... negative?

Answer 1

SOLVED!

The issue was in the function mb_detect_order(), this function just don't work as I was expecting. I was thinking this was a list of full supporting encoding order by mostly used in order to speed up the detection process.

But I just found that this function return just 2 encoding:

//print_r(mb_detect_order());
Array
(
    [0] => ASCII
    [1] => UTF-8
)

Which is almost completly useless in my case. MB functions can detect much more charset. You can check them out by run mb_list_encodings() and get the full list:

//print_r(mb_list_encodings());
Array
(
    [0] => pass
    [1] => auto
    [2] => wchar
    [3] => byte2be
    [4] => byte2le
    [5] => byte4be
    [6] => byte4le
    [7] => BASE64
    [8] => UUENCODE
    [9] => HTML-ENTITIES
    [10] => Quoted-Printable
    [11] => 7bit
    [12] => 8bit
    [13] => UCS-4
    [14] => UCS-4BE
    [15] => UCS-4LE
    [16] => UCS-2
    [17] => UCS-2BE
    [18] => UCS-2LE
    [19] => UTF-32
    [20] => UTF-32BE
    [21] => UTF-32LE
    [22] => UTF-16
    [23] => UTF-16BE
    [24] => UTF-16LE
    [25] => UTF-8
    [26] => UTF-7
    [27] => UTF7-IMAP
    [28] => ASCII
    [29] => EUC-JP
    [30] => SJIS
    [31] => eucJP-win
    [32] => EUC-JP-2004
    [33] => SJIS-win
    [34] => SJIS-Mobile#DOCOMO
    [35] => SJIS-Mobile#KDDI
    [36] => SJIS-Mobile#SOFTBANK
    [37] => SJIS-mac
    [38] => SJIS-2004
    [39] => UTF-8-Mobile#DOCOMO
    [40] => UTF-8-Mobile#KDDI-A
    [41] => UTF-8-Mobile#KDDI-B
    [42] => UTF-8-Mobile#SOFTBANK
    [43] => CP932
    [44] => CP51932
    [45] => JIS
    [46] => ISO-2022-JP
    [47] => ISO-2022-JP-MS
    [48] => GB18030
    [49] => Windows-1252
    [50] => Windows-1254
    [51] => ISO-8859-1
    [52] => ISO-8859-2
    [53] => ISO-8859-3
    [54] => ISO-8859-4
    [55] => ISO-8859-5
    [56] => ISO-8859-6
    [57] => ISO-8859-7
    [58] => ISO-8859-8
    [59] => ISO-8859-9
    [60] => ISO-8859-10
    [61] => ISO-8859-13
    [62] => ISO-8859-14
    [63] => ISO-8859-15
    [64] => ISO-8859-16
    [65] => EUC-CN
    [66] => CP936
    [67] => HZ
    [68] => EUC-TW
    [69] => BIG-5
    [70] => CP950
    [71] => EUC-KR
    [72] => UHC
    [73] => ISO-2022-KR
    [74] => Windows-1251
    [75] => CP866
    [76] => KOI8-R
    [77] => KOI8-U
    [78] => ArmSCII-8
    [79] => CP850
    [80] => JIS-ms
    [81] => ISO-2022-JP-2004
    [82] => ISO-2022-JP-MOBILE#KDDI
    [83] => CP50220
    [84] => CP50220raw
    [85] => CP50221
    [86] => CP50222
)

I was in wrong, thinking that mb_detect_order was just an ordered version of this list. The mb_detect_order is just.... useless. In order to encode in UTF8 in the right way use the following code:

$my_encoding_list = [
    "UTF-8",
    "UTF-7",
    "UTF-16",
    "UTF-32",
    "ISO-8859-16",
    "ISO-8859-15",
    "ISO-8859-10",
    "ISO-8859-1",
    "Windows-1254",
    "Windows-1252",
    "Windows-1251",
    "ASCII",
    //add yours preferred
];

//remove unsupported encodings
$encoding_list = array_intersect($my_encoding_list, mb_list_encodings());

//detect 'finally' the encoding
$this->encoding = mb_detect_encoding($source,$encoding_list,true);

This worked and solved my issue with bad data saved in the database.