Bug 1419168 - Add a .gitattributes file to force Linux line endings (#2997)

This prevents `$'\r': command not found` bash errors caused by CRLFs
when Windows hosts have suboptimal global Git configurations, meaning
one less thing that can go wrong / that needs documenting.

See:
https://help.github.com/articles/dealing-with-line-endings/
https://git-scm.com/docs/gitattributes
https://github.com/alexkaratarakis/gitattributes/blob/master/Web.gitattributes

.gitattributes

@@ -0,0 +1,195 @@
+# This file ensures that:
+# * on OS X/Linux: no CRLFs are accidentally checked into the repo.
+# * on Windows: the source checkout always uses LF line endings, even if the Git
+#   global config is using a suboptimal `core.autocrlf` setting (as is the default).
+#   This prevents `$'\r': command not found` bash errors caused by CRLFs.
+
+# Fallback for anything not listed below.
+# Note: Git prior to v2.10 has a bug where it treats this as `text` not `text=auto`,
+# but this isn't a problem since the fallback will be mostly unused.
+* text=auto eol=lf
+
+# The below is taken from:
+# https://github.com/alexkaratarakis/gitattributes/blob/master/Web.gitattributes
+# With a `s/text( eol=crlf)?$/text eol=lf/`.
+
+## SOURCE CODE
+*.bat      text eol=lf
+*.coffee   text eol=lf
+*.css      text eol=lf
+*.htm      text eol=lf
+*.html     text eol=lf
+*.inc      text eol=lf
+*.ini      text eol=lf
+*.js       text eol=lf
+*.json     text eol=lf
+*.jsx      text eol=lf
+*.less     text eol=lf
+*.od       text eol=lf
+*.onlydata text eol=lf
+*.php      text eol=lf
+*.pl       text eol=lf
+*.py       text eol=lf
+*.rb       text eol=lf
+*.sass     text eol=lf
+*.scm      text eol=lf
+*.scss     text eol=lf
+*.sh       text eol=lf
+*.sql      text eol=lf
+*.styl     text eol=lf
+*.tag      text eol=lf
+*.ts       text eol=lf
+*.tsx      text eol=lf
+*.xml      text eol=lf
+*.xhtml    text eol=lf
+
+## DOCKER
+*.dockerignore    text eol=lf
+Dockerfile    text eol=lf
+
+## DOCUMENTATION
+*.markdown   text eol=lf
+*.md         text eol=lf
+*.mdwn       text eol=lf
+*.mdown      text eol=lf
+*.mkd        text eol=lf
+*.mkdn       text eol=lf
+*.mdtxt      text eol=lf
+*.mdtext     text eol=lf
+*.txt        text eol=lf
+AUTHORS      text eol=lf
+CHANGELOG    text eol=lf
+CHANGES      text eol=lf
+CONTRIBUTING text eol=lf
+COPYING      text eol=lf
+copyright    text eol=lf
+*COPYRIGHT*  text eol=lf
+INSTALL      text eol=lf
+license      text eol=lf
+LICENSE      text eol=lf
+NEWS         text eol=lf
+readme       text eol=lf
+*README*     text eol=lf
+TODO         text eol=lf
+
+## TEMPLATES
+*.dot        text eol=lf
+*.ejs        text eol=lf
+*.haml       text eol=lf
+*.handlebars text eol=lf
+*.hbs        text eol=lf
+*.hbt        text eol=lf
+*.jade       text eol=lf
+*.latte      text eol=lf
+*.mustache   text eol=lf
+*.njk        text eol=lf
+*.phtml      text eol=lf
+*.tmpl       text eol=lf
+*.tpl        text eol=lf
+*.twig       text eol=lf
+
+## LINTERS
+.csslintrc    text eol=lf
+.eslintrc     text eol=lf
+.htmlhintrc   text eol=lf
+.jscsrc       text eol=lf
+.jshintrc     text eol=lf
+.jshintignore text eol=lf
+.stylelintrc  text eol=lf
+
+## CONFIGS
+*.bowerrc      text eol=lf
+*.cnf          text eol=lf
+*.conf         text eol=lf
+*.config       text eol=lf
+.browserslistrc    text eol=lf
+.editorconfig  text eol=lf
+.gitattributes text eol=lf
+.gitconfig     text eol=lf
+.gitignore     text eol=lf
+.htaccess      text eol=lf
+*.npmignore    text eol=lf
+*.yaml         text eol=lf
+*.yml          text eol=lf
+browserslist   text eol=lf
+Makefile       text eol=lf
+makefile       text eol=lf
+
+## HEROKU
+Procfile    text eol=lf
+.slugignore text eol=lf
+
+## GRAPHICS
+*.ai   binary
+*.bmp  binary
+*.eps  binary
+*.gif  binary
+*.ico  binary
+*.jng  binary
+*.jp2  binary
+*.jpg  binary
+*.jpeg binary
+*.jpx  binary
+*.jxr  binary
+*.pdf  binary
+*.png  binary
+*.psb  binary
+*.psd  binary
+*.svg  text eol=lf
+*.svgz binary
+*.tif  binary
+*.tiff binary
+*.wbmp binary
+*.webp binary
+
+## AUDIO
+*.kar  binary
+*.m4a  binary
+*.mid  binary
+*.midi binary
+*.mp3  binary
+*.ogg  binary
+*.ra   binary
+
+## VIDEO
+*.3gpp binary
+*.3gp  binary
+*.as   binary
+*.asf  binary
+*.asx  binary
+*.fla  binary
+*.flv  binary
+*.m4v  binary
+*.mng  binary
+*.mov  binary
+*.mp4  binary
+*.mpeg binary
+*.mpg  binary
+*.ogv  binary
+*.swc  binary
+*.swf  binary
+*.webm binary
+
+## ARCHIVES
+*.7z  binary
+*.gz  binary
+*.jar binary
+*.rar binary
+*.tar binary
+*.zip binary
+
+## FONTS
+*.ttf   binary
+*.eot   binary
+*.otf   binary
+*.woff  binary
+*.woff2 binary
+
+## EXECUTABLES
+*.exe binary
+*.pyc binary
+
+## Treeherder-specific extras
+## (Only need to list binary files here, text files can't be broken by `text=auto`)
+*.log binary
+*.xcf binary

docs/troubleshooting.rst

@@ -26,11 +26,3 @@ Errors during Vagrant setup
 * If you encounter an error saying *"The guest machine entered an invalid state while waiting for it to boot. Valid states are 'starting, running'. The machine is in the 'poweroff' state. Please verify everything is configured properly and try again."* you should should check your host machine's virtualization technology (vt-x) is enabled in the BIOS (see this guide_), then continue with ``vagrant up``.
 
   .. _guide: http://www.sysprobs.com/disable-enable-virtualization-technology-bios
-
-* On Windows, if upon running ``vagrant ssh`` you see the error *"/home/vagrant/.bash_aliases: line 1: syntax error near unexpected token `$'{\r''"* - it means your global Git line endings configuration is not correct. On the host machine run:
-
-  .. code-block:: bash
-
-    git config --global core.autocrlf input
-
-  You will then need to delete and reclone the repo (or else do a force checkout).