From a32dceff1ecee70cd9b7541a6e8e82b14bd01e10 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ionu=C8=9B=20G=2E=20Stan?= <ionut.g.stan@gmail.com>
Date: Fri, 20 Sep 2024 19:58:34 +0300
Subject: [PATCH] bash: configure default value of BASH_LOADABLES_PATH

See: https://www.gnu.org/software/bash/manual/html_node/Bash-Builtins.html#index-enable
See: http://git.savannah.gnu.org/cgit/bash.git/tree/config-top.h#n80

This enables shorter syntax for loading stock Bash builtins. For example,
instead of doing this:

    enable -f $(brew --prefix)/lib/bash/csv csv

the user can now load the `csv` builtin directly:

    enable csv

To complete the example, we can now do this:

    $ echo $BASH_LOADABLES_PATH
    /opt/homebrew/Cellar/bash/5.2.32/lib/bash:/usr/local/lib/bash:/usr/lib/bash:/opt/local/lib/bash:/usr/pkg/lib/bash:/opt/pkg/lib/bash:.
    $ type csv
    -bash: type: csv: not found
    $ enable csv
    $ type csv
    csv is a shell builtin
    $ help csv
    csv: csv [-a ARRAY] string
       Read comma-separated fields from a string.

       Parse STRING, a line of comma-separated values, into individual fields,
       and store them into the indexed array ARRAYNAME starting at index 0.
       If ARRAYNAME is not supplied, "CSV" is the default array name.
    $ csv 'a,"b",c'
    $ declare -p CSV
    declare -a CSV=([0]="a" [1]="b" [2]="c")
    $ enable -n csv
    $ type csv
    -bash: type: csv: not found
---
 Formula/b/bash.rb | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/Formula/b/bash.rb b/Formula/b/bash.rb
index 2c026ea90052..352ba55ca701 100644
--- a/Formula/b/bash.rb
+++ b/Formula/b/bash.rb
@@ -112,11 +112,24 @@ def install
     # Homebrew's bash instead of /bin/bash.
     ENV.append_to_cflags "-DSSH_SOURCE_BASHRC"
 
+    bash_loadables_path=[
+      "#{lib}/bash",
+      # Stock Bash paths; keep them for backwards compatibility.
+      "/usr/local/lib/bash",
+      "/usr/lib/bash",
+      "/opt/local/lib/bash",
+      "/usr/pkg/lib/bash",
+      "/opt/pkg/lib/bash",
+      ".",
+    ].join(":")
+    ENV.append_to_cflags "-DDEFAULT_LOADABLE_BUILTINS_PATH='\"#{bash_loadables_path}\"'"
+
     system "./configure", "--prefix=#{prefix}"
     system "make", "install"
   end
 
   test do
-    assert_equal "hello", shell_output("#{bin}/bash -c \"echo -n hello\"")
+    assert_equal "hello", shell_output("#{bin}/bash -c 'echo -n hello'")
+    assert_equal "csv is a shell builtin\n", shell_output("#{bin}/bash -c 'enable csv; type csv'")
   end
 end