test rebuilding a C file when a header dependency changes

spec/build_tests_spec.rb

@@ -81,4 +81,20 @@ describe Rscons do
       `./header`.should =~ /The value is 33/
     end
   end
+
+  it 'rebuilds a C source when a header it uses changes' do
+    setup_testdir(['header.c', 'header.h']) do
+      env = Rscons::Environment.new
+      env.Program('header', 'header.c')
+      File.exist?('header.o').should be_true
+      `./header`.should =~ /The value is 33/
+      h = File.read('header.h')
+      File.open('header.h', 'w') do |fh|
+        fh.puts h.sub('33', '42')
+      end
+      clear_cache
+      env.Program('header', 'header.c')
+      `./header`.should =~ /The value is 42/
+    end
+  end
 end