svg xml with weird non-utf8 content causes an ugly traceback

[Daniel Manrique]

how to reproduce:

- go to snapcraft.io, developer account, choose any snap...
- try to upload the specially-crafted evil svg, contains something like this (best to download the attachment, as the key is the funky xpacked non-utf8 data):
<?xml version="1.0" standalone="no"?>
<svg width="600" height="800">
<?xpacket begin="�"" id="W5M0MpCehiHzreSzNTczkc9d"?>
  <rect width="600" height="800" style="fill:rgb(0,0,255)" />
  <circle cx="300" cy="400" r="300" style="fill:rgb(255,0,0)" />
</svg>

Expected result:
- "Icon: The image file 'bogon.svg' is not valid (we can't open it)."
- No sentry tracebacks because we don't need to be spammed every time someone uploads a weird file

Actual result:
- "Icon: The image file 'bogon.svg' is not valid (we can't open it)." (OK, nice friendly user-facing error)
- A sentry traceback!!

https://sentry.ols.canonical.com/canonical/snapcraft-dashboard/issues/7976/

IOError: Could not convert SVG file: Error reading SVG:Error domain 1 code 9 on line 1 column 1 of file:///tmp/tmp_q0iEj.svg: Input is not proper UTF-8, indicate encoding !
Bytes: 0xFF 0x22 0x22 0x20

  File "devportal/forms.py", line 457, in make_icon_file
    data = make_icon_png_file(data, size, enforce_size=enforce_size)
  File "devportal/forms.py", line 432, in make_icon_png_file
    data = _make_simple_png_uploaded_file(data, size)
  File "devportal/forms.py", line 396, in _make_simple_png_uploaded_file
    raise IOError(msg)

Worth checking if we really want to bubble this to a sentry error. The file is clearly malformed, which appears to be due to a bug in inkscape (although without access to the file that triggered this originally, we can't tell whether it was indeed created by inkscape).

Without access to rsvg-convert, it's likely the user wouldn't have way of verifying why inkscape can open the file but we can't.

[Daniel Manrique (roadmr)]

https://bugs.launchpad.net/ubuntu/+source/inkscape/+bug/499257

[Daniel Manrique (roadmr)]

On our side, this is working as implemented - the code handles malformed svgs properly, but logger.exception()'s which results in sentry alerts, the rationale being that we do want to know when someone tries to upload a malformed svg and why.

Options would be to logger.warning instead so we have it in the logs but not raising sentry alerts, or using another svg parser/renderer which can grok those faily inkscape svgs.