Make grit <include> de-duping clearer.

R=tbreisacher@chromium.org
BUG=none
TEST=code is easier to read and more thoroughly tested
NOTRY=true

Review URL: https://codereview.chromium.org/800043003

Cr-Commit-Position: refs/heads/master@{#308693}

2 files changed, 17 insertions, 6 deletions

diff --git a/third_party/closure_compiler/processor.py b/third_party/closure_compiler/processor.py
index d25f8c0..af88862 100644
--- a/third_party/closure_compiler/processor.py
+++ b/third_party/closure_compiler/processor.py
@@ -86,13 +86,14 @@ class Processor(object):
       if match:
         file_dir = os.path.dirname(current_line[0])
         file_name = os.path.abspath(os.path.join(file_dir, match.group(1)))
-        if file_name in self._included_files:
-          self._lines[self._index] = self._lines[self._index][:2] + ("",)
-          self._index += 1
-        else:
+        if file_name not in self._included_files:
           self._include_file(file_name)
-      else:
-        self._index += 1
+          continue  # Stay on the same line.
+        else:
+          # Found a duplicate <include>. Ignore and insert a blank line to
+          # preserve line numbers.
+          self._lines[self._index] = self._lines[self._index][:2] + ("",)
+      self._index += 1
 
     for i, line in enumerate(self._lines):
       self._lines[i] = line[:2] + (re.sub(self._IF_TAGS_REG, "", line[2]),)
diff --git a/third_party/closure_compiler/processor_test.py b/third_party/closure_compiler/processor_test.py
index 942d472..f5517cc 100755
--- a/third_party/closure_compiler/processor_test.py
+++ b/third_party/closure_compiler/processor_test.py
@@ -39,6 +39,11 @@ debug(global);
 // Here continues checked.js, a swell file.
 """.strip()
 
+    FileCache._cache["/double-debug.js"] = """
+<include src="/debug.js">
+<include src="/debug.js">
+""".strip()
+
     self._processor = Processor("/checked.js")
 
   def testInline(self):
@@ -77,6 +82,11 @@ debug(global);
     self.assertEquals(set(["/global.js", "/debug.js"]),
                       self._processor.included_files)
 
+  def testDoubleIncludedSkipped(self):
+    """Verify that doubly included files are skipped."""
+    processor = Processor("/double-debug.js")
+    self.assertEquals(set(["/debug.js"]), processor.included_files)
+    self.assertEquals(FileCache.read("/debug.js") + "\n", processor.contents)
 
 class IfStrippingTest(unittest.TestCase):
   """Test that the contents of XML <if> blocks are stripped."""