Don't set git email if no email config in .pairs

bin/git-pair

@@ -22,6 +22,8 @@ Create a `.pairs` config file in project root or your home folder.
       eh: Edward Hieatt
       js: Josh Susser; jsusser
       sf: Serguei Filimonov; serguei
+    # if email section is present, email will be set
+    # if you leave out the email config section, email will not be set
     email:
       prefix: pair
       domain: pivotallabs.com
@@ -126,6 +128,10 @@ def extract_author_names_and_email_ids_from_config(config, initials)
   end.transpose
 end
 
+def no_email(config)
+   !config.key? 'email'
+end
+
 git_dir = `git rev-parse --git-dir`.chomp
 exit 1 if git_dir.empty?
 
@@ -137,12 +143,14 @@ global = " --global" if options[:global] or config["global"]
 if initials.any?
   author_names, email_ids = extract_author_names_and_email_ids_from_config(config, initials)
   authors = [author_names[0..-2].join(", "), author_names.last].reject(&:empty?).join(" and ")
-  email = build_email(email_ids, config["email"])
-
-  set_git_config global, :name => authors, :email => email, :initials => initials.join(" ")
+  git_config = {:name => authors,  :initials => initials.join(" ")}
+  git_config[:email] = build_email(email_ids, config["email"]) unless no_email(config)
+  set_git_config global,  git_config
 else
-  set_git_config global, :name => nil, :email => nil, :initials => nil
-  puts "Unset#{global} user.name, user.email, user.initials"
+  git_config = {:name => nil,  :initials => nil}
+  git_config[:email] = nil unless no_email(config)
+  set_git_config global, git_config
+  puts "Unset#{global} user.name, #{'user.email, ' unless no_email(config)}user.initials"
 end
 
 [:name, :email, :initials].each do |key|

spec/cli_spec.rb

@@ -82,6 +82,11 @@ def expect_config(result, name, initials, email, options={})
       result.should include "#{prefix}user.email #{email}"
     end
 
+    def git_config_value(name, global = false)
+      global_prefix = "cd /tmp && " if global
+      `#{global_prefix}git config user.#{name}`
+    end
+
     it "prints help" do
       result = run "git-pair --help"
       result.should include("Configures git authors when pair programming")
@@ -183,6 +188,22 @@ def expect_config(result, name, initials, email, options={})
         expect_config result, "Aa Bb", "ab", "foo@bar.com"
       end
 
+      context "when no email config is present" do
+        before do
+          write ".pairs", File.read(".pairs").sub(/email:.*/m, "")
+        end
+
+        it "doesn't set email" do
+          run "git pair ab"
+          git_config_value('email').should be_empty
+        end
+
+        it "doesn't report about email" do
+          result = run "git pair ab"
+          result.should_not include "email"
+        end
+      end
+
       it "uses no email prefix when only host is given" do
         write ".pairs", File.read(".pairs").sub(/email:.*/m, "email:\n  domain: foo.com")
         result = run "git pair ab"