postcalc.usps.com - see bug description

[webcompat-bot]

URL: https://postcalc.usps.com/Calculator/ShapeAndSize?country=0&ccode=US&oz=94041&omil=False&dz=92103&dmil=False&mdt=8%2F5%2F2017&mdz=11%3A59&m=0

Browser / Version: Firefox 54.0
Operating System: Ubuntu
Tested Another Browser: Yes

Problem type: Something else
Description: When I enter a larger weight than allowed (205) backspace stops working in the pounds box.
Steps to Reproduce:

1. Go to this url:

https://postcalc.usps.com/Calculator/ShapeAndSize?country=0&ccode=US&oz=94041&omil=False&dz=92103&dmil=False&mdt=8%2F5%2F2017&mdz=11%3A59&m=0

2. In the pounds box enter "205" (or any other large number)

3. Try pressing backspace

From webcompat.com with ❤️

[MDTsai]

Confirmed, I can reproduce using Firefox 57 on Linux. Move to needsdiagnosis.

[wisniewskit]

This looks like a site script bug. The problem is here in their HTML:

  <script type="text/javascript">
    $(document).ready(function () {
      $('.numeric-only').keypress(function (e) { NumberOnly(e); });
      $('.decimal-only').keypress(function (e) { DecimalOnly(e); });
    });

    function NumberOnly(e) {
      var verified = (e.which == 8 || e.which == undefined || e.which == 0) ? null : String.fromCharCode(e.which).match(/[^0-9]/);
      if (verified) { e.preventDefault();
      }
    }

    function DecimalOnly(e) {
      var verified = (e.which == 8 || e.which == undefined || e.which == 0) ? null : String.fromCharCode(e.which).match(/[0-9]|[.]/);
      if (!verified) { e.preventDefault(); }
    }
  </script>

Note that only Firefox sends keypress events for backspace and other control keys these days, so only it will end up calling this code. And here they're expressly forbidding backspace (e.which==8), as well as control keys (e.which==0). As such only Firefox will be affected by this bug.

In fact, to me it looks like they were trying to account for this browser difference, but ended up writing the reverse logic that they intended. This should work just fine (in both of those event handlers):

      var verified = e.which == 8 || e.which == undefined || e.which == 0 || String.fromCharCode(e.which).match(/[0-9]|[.]/);

Note that bug 968056 is about fixing this old interop issue, so I'll mark this as a dupe of that, but also as needscontact due to having a workaround.

[adamopenweb]

Maybe not worth contacting the site now, since we are trying to land a fix for https://bugzilla.mozilla.org/show_bug.cgi?id=968056.

When testing with
dom.keyboardevent.keypress.dispatch_non_printable_keys_only_system_group_in_content set to true, the backspace key works as expected.

[adamopenweb]

Setting this as severity-minor until we've figured out https://bugzilla.mozilla.org/show_bug.cgi?id=968056.

[softvision-sergiulogigan]

This seems to be fixed now.

Tested with:
Browser / Version: Firefox Nightly 72.0a1 (2019-11-03)
Operating System: Linux Mint