From e0a8ddcd1ef379ea235e6f34b957573f763494bb Mon Sep 17 00:00:00 2001
From: Max Howell <max@methylblue.com>
Date: Thu, 15 Mar 2012 16:37:46 +0000
Subject: [PATCH] Warn about broken symlinks in HOMEBREW_PREFIX

Refs Homebrew/homebrew#10874.
---
 Library/Homebrew/cmd/doctor.rb | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Library/Homebrew/cmd/doctor.rb b/Library/Homebrew/cmd/doctor.rb
index 04696da32a..4a981f7ca8 100644
--- a/Library/Homebrew/cmd/doctor.rb
+++ b/Library/Homebrew/cmd/doctor.rb
@@ -166,6 +166,21 @@ def check_for_other_package_managers
   end
 end
 
+def check_for_broken_symlinks
+  broken_symlinks = []
+  %w[lib include sbin bin etc share].each do |d|
+    d = HOMEBREW_PREFIX/d
+    d.find do |pn|
+      broken_symlinks << pn if pn.symlink? and pn.readlink.expand_path.to_s =~ /^#{HOMEBREW_PREFIX}/ and not pn.exist?
+    end
+  end
+  unless broken_symlinks.empty? then <<-EOS.undent
+    Broken symlinks were found. Remove them with `brew prune':
+      #{broken_symlinks * "\n      "}
+    EOS
+  end
+end
+
 def check_gcc_42
   if MacOS.gcc_42_build_version == nil
     # Don't show this warning on Xcode 4.2+