From 85389705679ffa47b5fed4dc2667ca621d7499bf Mon Sep 17 00:00:00 2001
From: Carlo Cabrera <30379873+carlocab@users.noreply.github.com>
Date: Mon, 22 Mar 2021 05:18:29 +0000
Subject: [PATCH 1/3] cmd/list: delineate formulae and casks

Listing everything without qualifying which is which is confusing for
some users.

Fixes #10897.
---
 Library/Homebrew/cmd/list.rb | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/Library/Homebrew/cmd/list.rb b/Library/Homebrew/cmd/list.rb
index c9cb629aa6..a11b7f21fb 100644
--- a/Library/Homebrew/cmd/list.rb
+++ b/Library/Homebrew/cmd/list.rb
@@ -116,8 +116,16 @@ module Homebrew
       ls_args << "-r" if args.r?
       ls_args << "-t" if args.t?
 
-      safe_system "ls", *ls_args, HOMEBREW_CELLAR unless args.cask?
-      list_casks(args: args) unless args.formula?
+      ohai "Formulae" if $stdout.tty? && !args.formula?
+      safe_system "ls", *ls_args, HOMEBREW_CELLAR
+
+      unless args.formula?
+        if $stdout.tty?
+          puts
+          ohai "Casks"
+        end
+        list_casks(args: args)
+      end
     elsif args.verbose? || !$stdout.tty?
       system_command! "find", args: args.named.to_kegs.map(&:to_s) + %w[-not -type d -print], print_stdout: true
     else

From a88d65acc7e6500d9318d17e6f6d092bb58a0dd4 Mon Sep 17 00:00:00 2001
From: Carlo Cabrera <30379873+carlocab@users.noreply.github.com>
Date: Mon, 22 Mar 2021 14:12:42 +0000
Subject: [PATCH 2/3] cmd/list: list casks only if one is installed

---
 Library/Homebrew/cmd/list.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Library/Homebrew/cmd/list.rb b/Library/Homebrew/cmd/list.rb
index a11b7f21fb..52f853ea66 100644
--- a/Library/Homebrew/cmd/list.rb
+++ b/Library/Homebrew/cmd/list.rb
@@ -119,7 +119,7 @@ module Homebrew
       ohai "Formulae" if $stdout.tty? && !args.formula?
       safe_system "ls", *ls_args, HOMEBREW_CELLAR
 
-      unless args.formula?
+      if !args.formula? && Cask::Caskroom.casks.any?
         if $stdout.tty?
           puts
           ohai "Casks"

From 4dccc2ef7f48e25a90a64701531bc88f2ffa31ef Mon Sep 17 00:00:00 2001
From: Carlo Cabrera <30379873+carlocab@users.noreply.github.com>
Date: Mon, 22 Mar 2021 17:15:56 +0000
Subject: [PATCH 3/3] cmd/list: list formulae only if one is installed

We need the `HOMEBREW_CELLAR.exist?` check to avoid errors in new
installations, which may not have a `Cellar` directory.
---
 Library/Homebrew/cmd/list.rb | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Library/Homebrew/cmd/list.rb b/Library/Homebrew/cmd/list.rb
index 52f853ea66..6d05addb80 100644
--- a/Library/Homebrew/cmd/list.rb
+++ b/Library/Homebrew/cmd/list.rb
@@ -116,8 +116,10 @@ module Homebrew
       ls_args << "-r" if args.r?
       ls_args << "-t" if args.t?
 
-      ohai "Formulae" if $stdout.tty? && !args.formula?
-      safe_system "ls", *ls_args, HOMEBREW_CELLAR
+      if HOMEBREW_CELLAR.exist? && HOMEBREW_CELLAR.children.any?
+        ohai "Formulae" if $stdout.tty? && !args.formula?
+        safe_system "ls", *ls_args, HOMEBREW_CELLAR
+      end
 
       if !args.formula? && Cask::Caskroom.casks.any?
         if $stdout.tty?