shells/fish -- arbitrary code execution via git

Peter Ammon reports:

	fish is a command line shell. fish version 3.1.0 through
	version 3.3.1 is vulnerable to arbitrary code execution.
	git repositories can contain per-repository
	configuration that change the behavior of git, including
	running arbitrary commands. When using the default
	configuration of fish, changing to a directory
	automatically runs git commands in order to display
	information about the current repository in the prompt.
	If an attacker can convince a user to change their
	current directory into one controlled by the attacker,
	such as on a shared file system or extracted archive,
	fish will run arbitrary commands under the attacker's
	control. This problem has been fixed in fish 3.4.0. Note
	that running git in these directories, including using
	the git tab completion, remains a potential trigger for
	this issue. As a workaround, remove the
	fish_git_prompt function from the prompt.