Installer can clobber local profile configuration

[connec]

Context:

The current logic for add_install_dir_to_path will write to the first file name in the list given to it if none of the files exist:

cargo-dist/cargo-dist/templates/installer/installer.sh.j2

Lines 465 to 472 in b9c9a51

	# If we didn't find anything, pick the first entry in the
	# list as the default to create and write to
	if [ -z "${_target:-}" ]; then
	local _rcfile_relative
	_rcfile_relative="$(echo "$_rcfiles" | awk '{ print $1 }')"
	_home="$(print_home_for_script "$_rcfile_relative")"
	_target="$_home/$_rcfile_relative"
	fi

add_install_dir_to_path is called three times, with different file names:

cargo-dist/cargo-dist/templates/installer/installer.sh.j2

Lines 398 to 403 in b9c9a51

	add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile"
	exit1=$?
	add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".bash_profile .bash_login .bashrc"
	exit2=$?
	add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".zshrc .zshenv"
	exit3=$?

Each call will therefore write at least one file (.profile, .bash_profile, .zshrc), regardless of which other files exist.

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Issue:

In my case, I use bash and put all my configuration in .profile. bash will only load .profile if a .bash_profile does not exist, so the current behaviour of the installer effectively clobbers my local profile.

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Possible solution:

Assuming this is undesired behaviour rather than an unsupported configuration at my end (though correct me if I'm wrong), this could be improved by making a single call to add_install_dir_to_path:

add_install_dir_to_path "$_install_dir_expr" "$_env_script_path" "$_env_script_path_expr" ".profile .bash_profile .bash_login .bashrc .zshrc .zshenv"

if [ $? = 1 ]; then
  # ...
fi

This would have the effect of creating ~/.profile if none of the files exist. As a lowest common denominator this seems like a reasonable choice.