Core ships with a .gitattributes file to improve git patches

A .gitattribute file defines certain attributes that apply to files inside a directory.
It is recursive for all sub-directories that are part of this repository.

The purpose of the file is to improve the output of git diff, and to enforce proper line-endings for files in the repository.

File extensions are grouped into two categories, drupaltext and drupalbinary.
For drupaltext, treat the following as errors:

• Trailing whitespace at the end of a line or tab character in the initial indent part of the line are treated as errors.
• Spaces are always allowed at the beginning of a line.
• Tabs, (while discouraged by our coding standards), are treated as 2 characters wide if present.
• Blank lines at the end of a file are not flagged as errors.

For drupalbinary, always include the binary diff in a patch instead of "binary files differ".

Force all text files to use LF, files with CRLF line-endings will be prevented from being checked in.

Furthermore, PHP files are given more intelligent context in patch files. Primarily, this means that a diff of code inside a method will show that method, and not just the class, at the top of the hunk.

The following extensions are defined as text files:

• *.css
• *.engine
• *.html
• *.inc
• *.info
• *.install
• *.js
• *.json
• *.lock
• *.md
• *.module
• *.php
• *.po
• *.script
• *.sh
• *.sql
• *.test
• *.txt
• *.xml
• *.yml

The following extensions are defined as binary files:

• *.gif
• *.gz
• *.ico
• *.jpg
• *.png
• *.phar

If a module, library, theme, or install profile you use has files that do not meet these criteria, you can include your own .gitattributes file and override these settings manually.