Unnecessary leading empty lines in index.html

[pwwang]

• I've read the contribution guidelines and agree with them

I've found a bug and checked that ...

• ... the problem doesn't occur with the default MkDocs template
• ... the problem is not in any of my customizations (CSS, JS, template)
• ... the documentation does not mention anything about my problem
• ... there are no open or closed issues that are related to my problem

Description

Unnecessary leading empty lines in index.html causing 404 in GH pages.

Expected behavior

<!doctype ... should be in the first line of the output HTML files.

Actual behavior

Leading empty lines observed.

Steps to reproduce the bug

1. mkdocs build
2. head site/index.html

Package versions

• Python: python --version 3.7.3
• MkDocs: mkdocs --version 1.1.2
• Material: pip show mkdocs-material | grep -E ^Version 6.1.0

Project configuration

site_name: liquidpy
theme:
    name: 'material'
markdown_extensions:
    - markdown.extensions.admonition
    - pymdownx.superfences:
        preserve_tabs: true
    - toc:
        baselevel: 2
extra_css:
    - style.css
nav:
    - 'Home': 'index.md'

And the head of my index.md (no leading empty lines):

# liquidpy
A port of [liquid][1] template engine for python

System information

• OS: Linux 3.10.0-1127.19.1.el7.x86_64 GitHub stars don't work if the repo_url ends with a / #1 SMP Tue Aug 11 19:12:04 EDT 2020 x86_64 x86_64 x86_64 GNU/Linux
• Browser: Chrome Version 73.0.3683.86

Also refer to this issue: mkdocs/mkdocs#2180

[squidfunk]

I see one empty line, when building the official documentation. Interestingly, it's been a long, long time like this and nobody had any problems. I've searched for an example that reproduces your issue and have found only counter examples, e.g.:

https://ing-bank.github.io/baker/

The project is hosted on GitHub pages and has the empty lines at the beginning, yet it doesn't 404:

[pwwang]

Thanks for the investigation.

Let me see if I can create a minimal repo to reproduce this.

[pwwang]

I myself could not reproduce it with this minimal repo:

https://github.com/pwwang/mkdocs-material-2020

I am closing this, as the issue is not caused by the theme.

Thank you.