Issue #17047: remove doubled words found in 2.7 to 3.4 Modules/*,
as reported by Serhiy Storchaka and Matthew Barnett.
diff --git a/Modules/zlib/deflate.c b/Modules/zlib/deflate.c
index 5c4022f..bcef67c 100644
--- a/Modules/zlib/deflate.c
+++ b/Modules/zlib/deflate.c
@@ -157,7 +157,7 @@
 
 /* ===========================================================================
  * Update a hash value with the given input byte
- * IN  assertion: all calls to to UPDATE_HASH are made with consecutive
+ * IN  assertion: all calls to UPDATE_HASH are made with consecutive
  *    input characters, so that a running hash key can be computed from the
  *    previous key instead of complete recalculation each time.
  */
@@ -170,7 +170,7 @@
  * the previous length of the hash chain.
  * If this file is compiled with -DFASTEST, the compression level is forced
  * to 1, and no hash chains are maintained.
- * IN  assertion: all calls to to INSERT_STRING are made with consecutive
+ * IN  assertion: all calls to INSERT_STRING are made with consecutive
  *    input characters and the first MIN_MATCH bytes of str are valid
  *    (except for the last MIN_MATCH-1 bytes of the input file).
  */