Unicode symbols not encoded properly in BarcodeImage[] in Mathematica 13.3

Question

Bug introduced in 13.2 or 13.3 and fixed in 14.1

Trying to generate a simple QR code with ← or U+2190. I got varying results: the same in Mathematica versions 12.3 and 13.1 but very different in version 13.3.

Mathematica 13.3 was updated to include explicit control for the error correction level. So I tried this code:

Table[BarcodeImage["\[LeftArrow]", {"QR", n}], {n, 0, 8}]

These all encode â and when pressing the search link from the stock iOS camera app it adds four ? to the end searching for "â????" in the web. Android sees the first character followed by two unrecognized characters.

I then tried using the following to refer to the desired character:

FromCharacterCode[{8592}, "UTF8"]
FromCharacterCode[{226, 134, 144}, "UTF8"]
"\:2190"
"\|E28690"

Though these do not give different results and the last line is not even a recognized symbol though I believe it should encode the same symbol. I also had similar problems in trying to encode different arrow characters such as ⬅ which encodes as ⬠and adds two ?? when the search link is pressed searching for â¬?? in the web or ⬠followed by a single unrecognized symbol on Android. This is really strange behavior but BarcodeImage[] seems to work fine for most other strings in 13.3. Is this a bug or am I missing something major here?

Answer 1

I am not super comfortable with peculiarities of character encodings in Mathematica, but I would say this is a regression bug introduced when they changed the external library used for QR generation (from ZXing Java Library to BarcodeTools.dll). You should report it to the WTS.

As a hacky workaround, you can try using:

fixBarcodeImage[args___] := Internal`InheritedBlock[{ToString},
  Unprotect[ToString];
  ToString[str_, CharacterEncoding -> "UTF-8"] := str;
  BarcodeImage[args]]

fixBarcodeImage["←"]