Move brew-leaves into core

Closes Homebrew/homebrew#24371.

Library/Contributions/cmd/brew-leaves.rb

@@ -1,29 +0,0 @@
-# Outputs formulae that are installed but are not a dependency for
-# any other installed formula.
-# See: http://github.com/mxcl/homebrew/issues/issue/1438
-
-require 'formula'
-require 'set'
-require 'tab'
-
-installed = Formula.installed
-deps_of_installed = Set.new
-
-installed.each do |f|
-  deps = []
-
-  f.deps.each do |dep|
-    if dep.optional? || dep.recommended?
-      tab = Tab.for_formula(f)
-      deps << dep.name if tab.with?(dep.name)
-    else
-      deps << dep.name
-    end
-  end
-
-  deps_of_installed.merge(deps)
-end
-
-installed.each do |f|
-  puts f.name unless deps_of_installed.include? f.name
-end

Library/Contributions/manpages/brew.1.md

@@ -197,6 +197,9 @@ Note that these flags should only appear after a command.
     If `--git` is passed, Homebrew will create a Git repository, useful for
     creating patches to the software.
 
+  * `leaves`:
+    Show installed formulae that are not dependencies of another installed formula.
+
   * `ln`, `link [--overwrite] [--dry-run] [--force]` <formula>:
     Symlink all of <formula>'s installed files into the Homebrew prefix. This
     is done automatically when you install formula, but can be useful for DIY

Library/Homebrew/cmd/leaves.rb

@@ -0,0 +1,29 @@
+require 'formula'
+require 'tab'
+require 'set'
+
+module Homebrew extend self
+  def leaves
+    installed = Formula.installed
+    deps_of_installed = Set.new
+
+    installed.each do |f|
+      deps = []
+
+      f.deps.each do |dep|
+        if dep.optional? || dep.recommended?
+          tab = Tab.for_formula(f)
+          deps << dep.name if tab.with?(dep.name)
+        else
+          deps << dep.name
+        end
+      end
+
+      deps_of_installed.merge(deps)
+    end
+
+    installed.each do |f|
+      puts f.name unless deps_of_installed.include? f.name
+    end
+  end
+end

share/man/man1/brew.1

@@ -218,6 +218,10 @@ Download and patch \fIformula\fR, then open a shell\. This allows the user to ru
 If \fB\-\-git\fR is passed, Homebrew will create a Git repository, useful for creating patches to the software\.
 .
 .TP
+\fBleaves\fR
+Show installed formulae that are not dependencies of another installed formula\.
+.
+.TP
 \fBln\fR, \fBlink [\-\-overwrite] [\-\-dry\-run] [\-\-force]\fR \fIformula\fR
 Symlink all of \fIformula\fR\'s installed files into the Homebrew prefix\. This is done automatically when you install formula, but can be useful for DIY installations\.
 .
@@ -560,7 +564,7 @@ If set, Homebrew will not use the GitHub API for e\.g searches or fetching relev
 .
 .TP
 HOMEBREW_INSTALL_BADGE
-Text printed before the installation summary of each successful build. Defaults to the beer emoji\.
+Text printed before the installation summary of each successful build\. Defaults to the beer emoji\.
 .
 .TP
 HOMEBREW_SOURCEFORGE_MIRROR