How to get git diff with full context?

Question

This seems to work pretty nicely:

git diff --no-prefix -U1000

With the caveat:

The -U flag specifies lines of context. You might need to increase this if there are more than 1000 lines between your changes.

I know this is old, but I also dislike hard-coded solutions, so I tested this:

git diff -U$(wc -l MYFILE)

Using -U seems to be the only way to approach the issue, but using a line count promises that it will work for even a small change in a very large file.

Note: git1.8.1rc1 announce (December 8th, 2012) includes:

A new configuration variable "diff.context" can be used to give the default number of context lines in the patch output, to override the hardcoded default of 3 lines.

so that could help, here, generate a more complete context.

Got inspiration and so I added a git alias.

$ cat ~/.gitconfig | fgrep diff
        df = "!git diff -U$(wc -l \"$1\" | cut -d ' ' -f 1) \"$1\""
$ git df <file>

Update:

Just found "git df" does not work sometimes, due to directory change when executing git alias. (See git aliases operate in the wrong directory). So this is the updated version:

$ cat ~/.gitconfig | fgrep df
        df = "! [ \"$GIT_PREFIX\" != \"\" ] && cd \"$GIT_PREFIX\"; ~/bin/git_df.sh"
$ 
$ cat ~/bin/git_df.sh
#!/bin/bash
for FILE in $@; do
    git diff -U$(wc -l "${FILE}" | cut -d ' ' -f 1) "${FILE}"
done
exit 0

This worked for me on macOS:

git diff -U$(wc -l main.htm | xargs)

see "How to trim whitespace from a Bash variable?"