Do not perform domain substitutions within comments

Covers C/C++, Java, Javascript and Python file extensions

Author: csagan5

utils/domain_substitution.py

@@ -15,6 +15,7 @@
 import io
 import os
 import re
+import string
 import tarfile
 import tempfile
 import zlib
@@ -102,19 +103,48 @@ def _substitute_path(path, regex_iter):
                 continue
         if not content:
             raise UnicodeDecodeError('Unable to decode with any encoding: %s' % path)
+
+        replace_comments = (path.suffix == '.java' or path.suffix == '.cc' or path.suffix == '.h'
+                            or path.suffix == '.js' or path.suffix == '.cpp' or path.suffix == '.c')
+        if replace_comments:
+            content = re.sub('(\/\*.*?\*/\n|\/\/.*?\n)', replaceComments, content, flags=re.DOTALL)
+        if path.suffix == '.py':
+            content = re.sub('(#.*?\n)', replaceComments, content, flags=re.DOTALL)
+            replace_comments = True
+
         file_subs = 0
         for regex_pair in regex_iter:
             content, sub_count = regex_pair.pattern.subn(regex_pair.replacement, content)
             file_subs += sub_count
         if file_subs > 0:
+            if replace_comments:
+                ## restore comments
+                content = re.sub(place_holder + '(\d+):', restoreComments, content)
+                comments = []
+
             substituted_content = content.encode(encoding)
             input_file.seek(0)
             input_file.write(content.encode(encoding))
             input_file.truncate()
             return (zlib.crc32(substituted_content), original_content)
+        comments = []
         return (None, None)
 
 
+## use a randomized placeholder for comments
+place_holder = ':C7yae7ozv:'
+comments = []
+
+
+def replaceComments(m):
+    comments.append(m.group(0))
+    return place_holder + str(len(comments)) + ':'
+
+
+def restoreComments(m):
+    return comments[int(m.group(1)) - 1]
+
+
 def _validate_file_index(index_file, resolved_tree, cache_index_files):
     """
     Validation of file index and hashes against the source tree.