Fix #650 (second try)

[pabloariasal]

This is a second try to fix the long standing bug reported in #650 in January 2018.
The first attempt was made in PR #656, but was abandoned and never merged.

In a nutshell, this bug doesn't allow the installed script to be called anything different than antigen.zsh, this is specially problematic if one wants to make antigen a hidden file. The proposed solution makes the name of the file dynamic.

[bbbco]

Shouldn't it be source "$_ANTIGEN_INSTALL_DIR/$_ANTIGEN_INSTALL_FILENAME" ... ?

[simonmarty]

The code is correct, ${0:A} will resolve to /home/$USER/antigen.zsh for ex.

[simonmarty]

I wrote up an identical fix before realizing there was already an open PR for this. Can the above be merged?

Tested on Ubuntu 24.04: Renamed antigen.zsh to someothername.zsh, added to .zshrc

source ~/someothername.zsh

antigen use oh-my-zsh

antigen apply

.antigen/init.zsh shows

antigen () {
  local MATCH MBEGIN MEND
  [[ "$ZSH_EVAL_CONTEXT" =~ "toplevel:*" || "$ZSH_EVAL_CONTEXT" =~ "cmdarg:*" ]] && source "/home/xxxxxxx/someothername.zsh" && eval antigen $@;
  return 0;
}

[simonmarty]

The code is correct, ${0:A} will resolve to /home/$USER/antigen.zsh for ex.