Don't load/save history or load rc if we can't find home.

Fixes: #477.
Signed-off-by: Jordon Bedwell <jordon@envygeeks.com>

lib/pry/pry_class.rb

@@ -249,7 +249,13 @@ class Pry
     config.history ||= OpenStruct.new
     config.history.should_save = true
     config.history.should_load = true
-    config.history.file = File.expand_path("~/.pry_history")
+    config.history.file = File.expand_path("~/.pry_history") rescue nil
+
+    if config.history.file.nil?
+      config.should_load_rc = false
+      config.history.should_save = false
+      config.history.should_load = false
+    end
 
     config.control_d_handler = DEFAULT_CONTROL_D_HANDLER
 

test/test_pry.rb

@@ -296,6 +296,17 @@ describe Pry do
           Object.remove_const(:TEST_RC)
         end
 
+        it "should not load the pryrc if it cannot expand ENV[HOME]" do
+          old_home = ENV['HOME']
+          old_rc = Pry.config.should_load_rc
+          ENV['HOME'] = nil
+          Pry.config.should_load_rc = true
+          lambda { Pry.start(self, :input => StringIO.new("exit-all\n"), :output => Pry::NullOutput) }.should.not.raise
+
+          ENV['HOME'] = old_home
+          Pry.config.should_load_rc = old_rc
+        end
+
         it "should not run the rc file at all if Pry.config.should_load_rc is false" do
           Pry.config.should_load_rc = false
           Pry.start(self, :input => StringIO.new("exit-all\n"), :output => Pry::NullOutput)