[SandboxAnalyzer] mark as changed Pods whose head state doesn't mathc

Closes #1160

lib/cocoapods/installer/analyzer/sandbox_analyzer.rb

@@ -150,6 +150,7 @@ module Pod
           return true if resolved_spec_names(pod) != sandbox_spec_names(pod)
           return true if sandbox.predownloaded?(pod)
           return true if folder_empty?(pod)
+          return true if sandbox.head_pod?(pod) != sandbox_head_verision?(pod)
           if update_mode
             return true if sandbox.head_pod?(pod)
           end
@@ -235,6 +236,13 @@ module Pod
           sandbox_manifest.checksum(pod)
         end
 
+        # @return [Bool] Wether the Pod is installed in the sandbox is in head
+        #         mode.
+        #
+        def sandbox_head_verision?(pod)
+          sandbox_version(pod).head? == true
+        end
+
         #--------------------------------------#
 
         def folder_exist?(pod)

spec/unit/installer/analyzer/sandbox_analyzer_spec.rb

@@ -88,6 +88,11 @@ module Pod
         @analyzer.send(:pod_changed?, 'BananaLib').should == true
       end
 
+      it "considers changed a Pod whose head state doesn't match" do
+        @sandbox.stubs(:head_pod?).returns(true)
+        @analyzer.send(:pod_changed?, 'BananaLib').should == true
+      end
+
       it "considers changed a Pod whose specification is in head mode if in update mode" do
         @sandbox.stubs(:head_pod?).returns(true)
         @analyzer.stubs(:update_mode).returns(true)
@@ -96,6 +101,7 @@ module Pod
 
       it "doesn't consider changed a Pod whose specification is in head mode if not in update mode" do
         @sandbox.stubs(:head_pod?).returns(true)
+        @analyzer.stubs(:sandbox_head_verision?).returns(true)
         @analyzer.stubs(:update_mode).returns(false)
         @analyzer.send(:pod_changed?, 'BananaLib').should == false
       end