document.baseURI is undefined in IE11

[antony]

Describe the bug

document.baseURI isn't usable in Internet Explorer, meaning Sapper 0.28.8 can't render pages due to the use of it in inject_styles.js.

Instead, an initial SSR render is shown, then a 500 page with the error cannot get property 'length' of undefined or null reference is displayed.

Logs

Unable to get property 'length' of undefined or null reference
 {"description":"Unable to get property 'length' of undefined or null reference","number":-2146823281,"stack":"TypeError: Unable to get property 'length' of undefined or null reference\n at Anonymous function (blob:1C66BD39-459E-4806-9A86-79C51EBAD409:1:316)\n a

To Reproduce
Checkout new sapper project
Add polyfills
Run in IE11

Expected behavior
Pages should render

• The output of npx envinfo --system --npmPackages svelte,sapper,rollup,webpack --binaries --browsers

  System:
  OS: Linux 5.4 Ubuntu 20.04.1 LTS (Focal Fossa)
  CPU: (4) x64 Intel(R) Core(TM) i7-5500U CPU @ 2.40GHz
  Memory: 169.85 MB / 7.68 GB
  Container: Yes
  Shell: 5.8 - /bin/zsh
  Binaries:
  Node: 12.18.3 - ~/.nvm/versions/node/v12.18.3/bin/node
  Yarn: 1.22.4 - ~/.nvm/versions/node/v12.18.3/bin/yarn
  npm: 6.14.6 - ~/.nvm/versions/node/v12.18.3/bin/npm
  Browsers:
  Chrome: 85.0.4183.121
  Firefox: 80.0.1
  npmPackages:
  rollup: ^2.3.4 => 2.28.1
  sapper: ^0.28.0 => 0.28.8
  svelte: ^3.17.3 => 3.26.0

• Your browser

IE11

Severity
Blocker

Additional context

Fixing this could also resolve the issue here:

#1034

[Conduitry]

This should be fixed in 0.28.9.