[PodTargetInstaller] spec 4 header_mappings_dir w. umbrella.h imports

Add spec for using relative paths inside the header_mappings_dir
if specified for umbrella header generation.

spec/unit/installer/target_installer/pod_target_installer_spec.rb

@@ -249,7 +249,8 @@ module Pod
 
       #--------------------------------------------------------------------------------#
 
-      it 'creates custom copy files phases for framework pods with header_mappings_dirs' do
+      describe 'concerning header_mappings_dirs' do
+        before do
           @project.add_pod_group('snake', fixture('snake'))
 
           @pod_target = fixture_pod_target('snake/snake.podspec', @target_definition)
@@ -261,7 +262,9 @@ module Pod
           end
           @installer.stubs(:target).returns(@pod_target)
           @installer.install!
+        end
 
+        it 'creates custom copy files phases for framework pods' do
           target = @project.native_targets.first
           target.name.should == 'snake'
 
@@ -292,6 +295,21 @@ module Pod
           ]
         end
 
+        it 'uses relative file paths to generate umbrella header' do
+          content = @pod_target.umbrella_header_path.read
+
+          content.should =~ %r{"A/Boa.h"}
+          content.should =~ %r{"A/Garden.h"}
+          content.should =~ %r{"A/Rattle.h"}
+          content.should =~ %r{"B/Boa.h"}
+          content.should =~ %r{"B/Garden.h"}
+          content.should =~ %r{"B/Rattle.h"}
+          content.should =~ %r{"C/Boa.h"}
+          content.should =~ %r{"C/Garden.h"}
+          content.should =~ %r{"C/Rattle.h"}
+        end
+      end
+
       #--------------------------------------------------------------------------------#
 
       describe 'concerning compiler flags' do