diff --git a/lib/puppet/util.rb b/lib/puppet/util.rb
index d25e4d382..737a9281c 100644
--- a/lib/puppet/util.rb
+++ b/lib/puppet/util.rb
@@ -1,427 +1,440 @@
 # A module to collect utility functions.
 
 require 'English'
 require 'puppet/util/monkey_patches'
 require 'sync'
 require 'tempfile'
 require 'puppet/external/lock'
 require 'puppet/error'
 require 'monitor'
 require 'puppet/util/execution_stub'
 require 'uri'
 
 module Puppet
 
 module Util
   require 'benchmark'
 
   # These are all for backward compatibility -- these are methods that used
   # to be in Puppet::Util but have been moved into external modules.
   require 'puppet/util/posix'
   extend Puppet::Util::POSIX
 
   @@sync_objects = {}.extend MonitorMixin
 
 
   def self.activerecord_version
     if (defined?(::ActiveRecord) and defined?(::ActiveRecord::VERSION) and defined?(::ActiveRecord::VERSION::MAJOR) and defined?(::ActiveRecord::VERSION::MINOR))
       ([::ActiveRecord::VERSION::MAJOR, ::ActiveRecord::VERSION::MINOR].join('.').to_f)
     else
       0
     end
   end
 
 
   # Run some code with a specific environment.  Resets the environment back to
   # what it was at the end of the code.
   def self.withenv(hash)
     saved = ENV.to_hash
     hash.each do |name, val|
       ENV[name.to_s] = val
     end
 
     yield
   ensure
     ENV.clear
     saved.each do |name, val|
       ENV[name] = val
     end
   end
 
 
   # Execute a given chunk of code with a new umask.
   def self.withumask(mask)
     cur = File.umask(mask)
 
     begin
       yield
     ensure
       File.umask(cur)
     end
   end
 
 
   def self.synchronize_on(x,type)
     sync_object,users = 0,1
     begin
       @@sync_objects.synchronize {
         (@@sync_objects[x] ||= [Sync.new,0])[users] += 1
       }
       @@sync_objects[x][sync_object].synchronize(type) { yield }
     ensure
       @@sync_objects.synchronize {
         @@sync_objects.delete(x) unless (@@sync_objects[x][users] -= 1) > 0
       }
     end
   end
 
   # Change the process to a different user
   def self.chuser
     if group = Puppet[:group]
       begin
         Puppet::Util::SUIDManager.change_group(group, true)
       rescue => detail
         Puppet.warning "could not change to group #{group.inspect}: #{detail}"
         $stderr.puts "could not change to group #{group.inspect}"
 
         # Don't exit on failed group changes, since it's
         # not fatal
         #exit(74)
       end
     end
 
     if user = Puppet[:user]
       begin
         Puppet::Util::SUIDManager.change_user(user, true)
       rescue => detail
         $stderr.puts "Could not change to user #{user}: #{detail}"
         exit(74)
       end
     end
   end
 
   # Create instance methods for each of the log levels.  This allows
   # the messages to be a little richer.  Most classes will be calling this
   # method.
   def self.logmethods(klass, useself = true)
     Puppet::Util::Log.eachlevel { |level|
       klass.send(:define_method, level, proc { |args|
         args = args.join(" ") if args.is_a?(Array)
         if useself
 
           Puppet::Util::Log.create(
             :level => level,
             :source => self,
             :message => args
           )
         else
 
           Puppet::Util::Log.create(
             :level => level,
             :message => args
           )
         end
       })
     }
   end
 
   # Proxy a bunch of methods to another object.
   def self.classproxy(klass, objmethod, *methods)
     classobj = class << klass; self; end
     methods.each do |method|
       classobj.send(:define_method, method) do |*args|
         obj = self.send(objmethod)
 
         obj.send(method, *args)
       end
     end
   end
 
   # Proxy a bunch of methods to another object.
   def self.proxy(klass, objmethod, *methods)
     methods.each do |method|
       klass.send(:define_method, method) do |*args|
         obj = self.send(objmethod)
 
         obj.send(method, *args)
       end
     end
   end
 
 
   def benchmark(*args)
     msg = args.pop
     level = args.pop
     object = nil
 
     if args.empty?
       if respond_to?(level)
         object = self
       else
         object = Puppet
       end
     else
       object = args.pop
     end
 
     raise Puppet::DevError, "Failed to provide level to :benchmark" unless level
 
     unless level == :none or object.respond_to? level
       raise Puppet::DevError, "Benchmarked object does not respond to #{level}"
     end
 
     # Only benchmark if our log level is high enough
     if level != :none and Puppet::Util::Log.sendlevel?(level)
       result = nil
       seconds = Benchmark.realtime {
         yield
       }
       object.send(level, msg + (" in %0.2f seconds" % seconds))
       return seconds
     else
       yield
     end
   end
 
   def which(bin)
     if absolute_path?(bin)
       return bin if FileTest.file? bin and FileTest.executable? bin
     else
       ENV['PATH'].split(File::PATH_SEPARATOR).each do |dir|
-        dest = File.expand_path(File.join(dir, bin))
+        begin
+          dest = File.expand_path(File.join(dir, bin))
+        rescue ArgumentError => e
+          # if the user's PATH contains a literal tilde (~) character and HOME is not set, we may get
+          # an ArgumentError here.  Let's check to see if that is the case; if not, re-raise whatever error
+          # was thrown.
+          raise e unless ((dir =~ /~/) && ((ENV['HOME'].nil? || ENV['HOME'] == "")))
+
+          # if we get here they have a tilde in their PATH.  We'll issue a single warning about this and then
+          # ignore this path element and carry on with our lives.
+          Puppet::Util::Warnings.warnonce("PATH contains a ~ character, and HOME is not set; ignoring PATH element '#{dir}'.")
+          next
+        end
         if Puppet.features.microsoft_windows? && File.extname(dest).empty?
           exts = ENV['PATHEXT']
           exts = exts ? exts.split(File::PATH_SEPARATOR) : %w[.COM .EXE .BAT .CMD]
           exts.each do |ext|
             destext = File.expand_path(dest + ext)
+
             return destext if FileTest.file? destext and FileTest.executable? destext
           end
         end
         return dest if FileTest.file? dest and FileTest.executable? dest
       end
     end
     nil
   end
   module_function :which
 
   # Determine in a platform-specific way whether a path is absolute. This
   # defaults to the local platform if none is specified.
   def absolute_path?(path, platform=nil)
     # Escape once for the string literal, and once for the regex.
     slash = '[\\\\/]'
     name = '[^\\\\/]+'
     regexes = {
       :windows => %r!^(([A-Z]:#{slash})|(#{slash}#{slash}#{name}#{slash}#{name})|(#{slash}#{slash}\?#{slash}#{name}))!i,
       :posix   => %r!^/!,
     }
     require 'puppet'
     platform ||= Puppet.features.microsoft_windows? ? :windows : :posix
 
     !! (path =~ regexes[platform])
   end
   module_function :absolute_path?
 
   # Convert a path to a file URI
   def path_to_uri(path)
     return unless path
 
     params = { :scheme => 'file' }
 
     if Puppet.features.microsoft_windows?
       path = path.gsub(/\\/, '/')
 
       if unc = /^\/\/([^\/]+)(\/[^\/]+)/.match(path)
         params[:host] = unc[1]
         path = unc[2]
       elsif path =~ /^[a-z]:\//i
         path = '/' + path
       end
     end
 
     params[:path] = URI.escape(path)
 
     begin
       URI::Generic.build(params)
     rescue => detail
       raise Puppet::Error, "Failed to convert '#{path}' to URI: #{detail}"
     end
   end
   module_function :path_to_uri
 
   # Get the path component of a URI
   def uri_to_path(uri)
     return unless uri.is_a?(URI)
 
     path = URI.unescape(uri.path)
 
     if Puppet.features.microsoft_windows? and uri.scheme == 'file'
       if uri.host
         path = "//#{uri.host}" + path # UNC
       else
         path.sub!(/^\//, '')
       end
     end
 
     path
   end
   module_function :uri_to_path
 
   # Create an exclusive lock.
   def threadlock(resource, type = Sync::EX)
     Puppet::Util.synchronize_on(resource,type) { yield }
   end
 
 
   module_function :benchmark
 
   def memory
     unless defined?(@pmap)
       @pmap = which('pmap')
     end
     if @pmap
       %x{#{@pmap} #{Process.pid}| grep total}.chomp.sub(/^\s*total\s+/, '').sub(/K$/, '').to_i
     else
       0
     end
   end
 
   def symbolize(value)
     if value.respond_to? :intern
       value.intern
     else
       value
     end
   end
 
   def symbolizehash(hash)
     newhash = {}
     hash.each do |name, val|
       if name.is_a? String
         newhash[name.intern] = val
       else
         newhash[name] = val
       end
     end
   end
 
   def symbolizehash!(hash)
     hash.each do |name, val|
       if name.is_a? String
         hash[name.intern] = val
         hash.delete(name)
       end
     end
 
     hash
   end
   module_function :symbolize, :symbolizehash, :symbolizehash!
 
   # Just benchmark, with no logging.
   def thinmark
     seconds = Benchmark.realtime {
       yield
     }
 
     seconds
   end
 
   module_function :memory, :thinmark
 
   def secure_open(file,must_be_w,&block)
     raise Puppet::DevError,"secure_open only works with mode 'w'" unless must_be_w == 'w'
     raise Puppet::DevError,"secure_open only requires a block"    unless block_given?
     Puppet.warning "#{file} was a symlink to #{File.readlink(file)}" if File.symlink?(file)
     if File.exists?(file) or File.symlink?(file)
       wait = File.symlink?(file) ? 5.0 : 0.1
       File.delete(file)
       sleep wait # give it a chance to reappear, just in case someone is actively trying something.
     end
     begin
       File.open(file,File::CREAT|File::EXCL|File::TRUNC|File::WRONLY,&block)
     rescue Errno::EEXIST
       desc = File.symlink?(file) ? "symlink to #{File.readlink(file)}" : File.stat(file).ftype
       puts "Warning: #{file} was apparently created by another process (as"
       puts "a #{desc}) as soon as it was deleted by this process.  Someone may be trying"
       puts "to do something objectionable (such as tricking you into overwriting system"
       puts "files if you are running as root)."
       raise
     end
   end
   module_function :secure_open
 
 
   # Because IO#binread is only available in 1.9
   def binread(file)
     File.open(file, 'rb') { |f| f.read }
   end
   module_function :binread
 
 
 
   # utility method to get the current call stack and format it to a human-readable string (which some IDEs/editors
   # will recognize as links to the line numbers in the trace)
   def self.pretty_backtrace()
     caller(1).collect do |line|
       file_path, line_num = line.split(":")
       file_path = expand_symlinks(File.expand_path(file_path))
 
       file_path + ":" + line_num
     end .join("\n")
 
   end
 
   # utility method that takes a path as input, checks each component of the path to see if it is a symlink, and expands
   # it if it is.  returns the expanded path.
   def self.expand_symlinks(file_path)
     file_path.split("/").inject do |full_path, next_dir|
       next_path = full_path + "/" + next_dir
       if File.symlink?(next_path) then
         link = File.readlink(next_path)
         next_path =
             case link
               when /^\// then link
               else
                 File.expand_path(full_path + "/" + link)
             end
       end
       next_path
     end
   end
 
 
 
   #######################################################################################################
   # Deprecated methods relating to process execution; these have been moved to Puppet::Util::Execution
   #######################################################################################################
 
   def execpipe(command, failonfail = true, &block)
     Puppet.deprecation_warning("Puppet::Util.execpipe is deprecated; please use Puppet::Util::Execution.execpipe")
     Puppet::Util::Execution.execpipe(command, failonfail, &block)
   end
   module_function :execpipe
 
   def execfail(command, exception)
     Puppet.deprecation_warning("Puppet::Util.execfail is deprecated; please use Puppet::Util::Execution.execfail")
     Puppet::Util::Execution.execfail(command, exception)
   end
   module_function :execfail
 
   def execute(command, arguments = {})
     Puppet.deprecation_warning("Puppet::Util::Execution.execute is deprecated; please use Puppet::Util::Execution.execute")
     Puppet::Util::Execution.execute(command, arguments)
   end
   module_function :execute
 
 end
 end
 
 
 require 'puppet/util/errors'
 require 'puppet/util/methodhelper'
 require 'puppet/util/metaid'
 require 'puppet/util/classgen'
 require 'puppet/util/docs'
 require 'puppet/util/execution'
 require 'puppet/util/logging'
 require 'puppet/util/package'
 require 'puppet/util/warnings'
diff --git a/spec/unit/util_spec.rb b/spec/unit/util_spec.rb
index 3369c49ec..3561f0135 100755
--- a/spec/unit/util_spec.rb
+++ b/spec/unit/util_spec.rb
@@ -1,296 +1,303 @@
 #!/usr/bin/env ruby
 
 require 'spec_helper'
 
 describe Puppet::Util do
   include PuppetSpec::Files
 
 
   describe "#withenv" do
     before :each do
       @original_path = ENV["PATH"]
       @new_env = {:PATH => "/some/bogus/path"}
     end
 
     it "should change environment variables within the block then reset environment variables to their original values" do
       Puppet::Util.withenv @new_env do
         ENV["PATH"].should == "/some/bogus/path"
       end
       ENV["PATH"].should == @original_path
     end
 
     it "should reset environment variables to their original values even if the block fails" do
       begin
         Puppet::Util.withenv @new_env do
           ENV["PATH"].should == "/some/bogus/path"
           raise "This is a failure"
         end
       rescue
       end
       ENV["PATH"].should == @original_path
     end
 
     it "should reset environment variables even when they are set twice" do
       # Setting Path & Environment parameters in Exec type can cause weirdness
       @new_env["PATH"] = "/someother/bogus/path"
       Puppet::Util.withenv @new_env do
         # When assigning duplicate keys, can't guarantee order of evaluation
         ENV["PATH"].should =~ /\/some.*\/bogus\/path/
       end
       ENV["PATH"].should == @original_path
     end
 
     it "should remove any new environment variables after the block ends" do
       @new_env[:FOO] = "bar"
       Puppet::Util.withenv @new_env do
         ENV["FOO"].should == "bar"
       end
       ENV["FOO"].should == nil
     end
 
   end
 
   describe "#absolute_path?" do
     it "should default to the platform of the local system" do
       Puppet.features.stubs(:posix?).returns(true)
       Puppet.features.stubs(:microsoft_windows?).returns(false)
 
       Puppet::Util.should be_absolute_path('/foo')
       Puppet::Util.should_not be_absolute_path('C:/foo')
 
       Puppet.features.stubs(:posix?).returns(false)
       Puppet.features.stubs(:microsoft_windows?).returns(true)
 
       Puppet::Util.should be_absolute_path('C:/foo')
       Puppet::Util.should_not be_absolute_path('/foo')
     end
 
     describe "when using platform :posix" do
       %w[/ /foo /foo/../bar //foo //Server/Foo/Bar //?/C:/foo/bar /\Server/Foo /foo//bar/baz].each do |path|
         it "should return true for #{path}" do
           Puppet::Util.should be_absolute_path(path, :posix)
         end
       end
 
       %w[. ./foo \foo C:/foo \\Server\Foo\Bar \\?\C:\foo\bar \/?/foo\bar \/Server/foo foo//bar/baz].each do |path|
         it "should return false for #{path}" do
           Puppet::Util.should_not be_absolute_path(path, :posix)
         end
       end
     end
 
     describe "when using platform :windows" do
       %w[C:/foo C:\foo \\\\Server\Foo\Bar \\\\?\C:\foo\bar //Server/Foo/Bar //?/C:/foo/bar /\?\C:/foo\bar \/Server\Foo/Bar c:/foo//bar//baz].each do |path|
         it "should return true for #{path}" do
           Puppet::Util.should be_absolute_path(path, :windows)
         end
       end
 
       %w[/ . ./foo \foo /foo /foo/../bar //foo C:foo/bar foo//bar/baz].each do |path|
         it "should return false for #{path}" do
           Puppet::Util.should_not be_absolute_path(path, :windows)
         end
       end
     end
   end
 
   describe "#path_to_uri" do
     %w[. .. foo foo/bar foo/../bar].each do |path|
       it "should reject relative path: #{path}" do
         lambda { Puppet::Util.path_to_uri(path) }.should raise_error(Puppet::Error)
       end
     end
 
     it "should perform URI escaping" do
       Puppet::Util.path_to_uri("/foo bar").path.should == "/foo%20bar"
     end
 
     describe "when using platform :posix" do
       before :each do
         Puppet.features.stubs(:posix).returns true
         Puppet.features.stubs(:microsoft_windows?).returns false
       end
 
       %w[/ /foo /foo/../bar].each do |path|
         it "should convert #{path} to URI" do
           Puppet::Util.path_to_uri(path).path.should == path
         end
       end
     end
 
     describe "when using platform :windows" do
       before :each do
         Puppet.features.stubs(:posix).returns false
         Puppet.features.stubs(:microsoft_windows?).returns true
       end
 
       it "should normalize backslashes" do
         Puppet::Util.path_to_uri('c:\\foo\\bar\\baz').path.should == '/' + 'c:/foo/bar/baz'
       end
 
       %w[C:/ C:/foo/bar].each do |path|
         it "should convert #{path} to absolute URI" do
           Puppet::Util.path_to_uri(path).path.should == '/' + path
         end
       end
 
       %w[share C$].each do |path|
         it "should convert UNC #{path} to absolute URI" do
           uri = Puppet::Util.path_to_uri("\\\\server\\#{path}")
           uri.host.should == 'server'
           uri.path.should == '/' + path
         end
       end
     end
   end
 
   describe ".uri_to_path" do
     require 'uri'
 
     it "should strip host component" do
       Puppet::Util.uri_to_path(URI.parse('http://foo/bar')).should == '/bar'
     end
 
     it "should accept puppet URLs" do
       Puppet::Util.uri_to_path(URI.parse('puppet:///modules/foo')).should == '/modules/foo'
     end
 
     it "should return unencoded path" do
       Puppet::Util.uri_to_path(URI.parse('http://foo/bar%20baz')).should == '/bar baz'
     end
 
     it "should be nil-safe" do
       Puppet::Util.uri_to_path(nil).should be_nil
     end
 
     describe "when using platform :posix",:if => Puppet.features.posix? do
       it "should accept root" do
         Puppet::Util.uri_to_path(URI.parse('file:/')).should == '/'
       end
 
       it "should accept single slash" do
         Puppet::Util.uri_to_path(URI.parse('file:/foo/bar')).should == '/foo/bar'
       end
 
       it "should accept triple slashes" do
         Puppet::Util.uri_to_path(URI.parse('file:///foo/bar')).should == '/foo/bar'
       end
     end
 
     describe "when using platform :windows", :if => Puppet.features.microsoft_windows? do
       it "should accept root" do
         Puppet::Util.uri_to_path(URI.parse('file:/C:/')).should == 'C:/'
       end
 
       it "should accept single slash" do
         Puppet::Util.uri_to_path(URI.parse('file:/C:/foo/bar')).should == 'C:/foo/bar'
       end
 
       it "should accept triple slashes" do
         Puppet::Util.uri_to_path(URI.parse('file:///C:/foo/bar')).should == 'C:/foo/bar'
       end
 
       it "should accept file scheme with double slashes as a UNC path" do
         Puppet::Util.uri_to_path(URI.parse('file://host/share/file')).should == '//host/share/file'
       end
     end
   end
 
   describe "#which" do
     let(:base) { File.expand_path('/bin') }
     let(:path) { File.join(base, 'foo') }
 
     before :each do
       FileTest.stubs(:file?).returns false
       FileTest.stubs(:file?).with(path).returns true
 
       FileTest.stubs(:executable?).returns false
       FileTest.stubs(:executable?).with(path).returns true
     end
 
     it "should accept absolute paths" do
       Puppet::Util.which(path).should == path
     end
 
     it "should return nil if no executable found" do
       Puppet::Util.which('doesnotexist').should be_nil
     end
 
+    it "should warn if the user's HOME is not set but their PATH contains a ~" do
+      Puppet::Util.withenv({:HOME => nil, :PATH => "~/bin:/usr/bin:/bin"}) do
+        Puppet::Util::Warnings.expects(:warnonce).once
+        Puppet::Util.which('foo').should_not be_nil
+      end
+    end
+
     it "should reject directories" do
       Puppet::Util.which(base).should be_nil
     end
 
     describe "on POSIX systems" do
       before :each do
         Puppet.features.stubs(:posix?).returns true
         Puppet.features.stubs(:microsoft_windows?).returns false
       end
 
       it "should walk the search PATH returning the first executable" do
         ENV.stubs(:[]).with('PATH').returns(File.expand_path('/bin'))
 
         Puppet::Util.which('foo').should == path
       end
     end
 
     describe "on Windows systems" do
       let(:path) { File.expand_path(File.join(base, 'foo.CMD')) }
 
       before :each do
         Puppet.features.stubs(:posix?).returns false
         Puppet.features.stubs(:microsoft_windows?).returns true
       end
 
       describe "when a file extension is specified" do
         it "should walk each directory in PATH ignoring PATHEXT" do
           ENV.stubs(:[]).with('PATH').returns(%w[/bar /bin].map{|dir| File.expand_path(dir)}.join(File::PATH_SEPARATOR))
 
           FileTest.expects(:file?).with(File.join(File.expand_path('/bar'), 'foo.CMD')).returns false
 
           ENV.expects(:[]).with('PATHEXT').never
           Puppet::Util.which('foo.CMD').should == path
         end
       end
 
       describe "when a file extension is not specified" do
         it "should walk each extension in PATHEXT until an executable is found" do
           bar = File.expand_path('/bar')
           ENV.stubs(:[]).with('PATH').returns("#{bar}#{File::PATH_SEPARATOR}#{base}")
           ENV.stubs(:[]).with('PATHEXT').returns(".EXE#{File::PATH_SEPARATOR}.CMD")
 
           exts = sequence('extensions')
           FileTest.expects(:file?).in_sequence(exts).with(File.join(bar, 'foo.EXE')).returns false
           FileTest.expects(:file?).in_sequence(exts).with(File.join(bar, 'foo.CMD')).returns false
           FileTest.expects(:file?).in_sequence(exts).with(File.join(base, 'foo.EXE')).returns false
           FileTest.expects(:file?).in_sequence(exts).with(path).returns true
 
           Puppet::Util.which('foo').should == path
         end
 
         it "should walk the default extension path if the environment variable is not defined" do
           ENV.stubs(:[]).with('PATH').returns(base)
           ENV.stubs(:[]).with('PATHEXT').returns(nil)
 
           exts = sequence('extensions')
           %w[.COM .EXE .BAT].each do |ext|
             FileTest.expects(:file?).in_sequence(exts).with(File.join(base, "foo#{ext}")).returns false
           end
           FileTest.expects(:file?).in_sequence(exts).with(path).returns true
 
           Puppet::Util.which('foo').should == path
         end
 
         it "should fall back if no extension matches" do
           ENV.stubs(:[]).with('PATH').returns(base)
           ENV.stubs(:[]).with('PATHEXT').returns(".EXE")
 
           FileTest.stubs(:file?).with(File.join(base, 'foo.EXE')).returns false
           FileTest.stubs(:file?).with(File.join(base, 'foo')).returns true
           FileTest.stubs(:executable?).with(File.join(base, 'foo')).returns true
 
           Puppet::Util.which('foo').should == File.join(base, 'foo')
         end
       end
     end
   end
 end