Upgrade to coverage 3.7.1 and have it auto-build itself on first use.

third_party/coverage-3.7.1/coverage/misc.py

Index: third_party/coverage-3.7.1/coverage/misc.py
diff --git a/third_party/coverage-3.6/coverage/misc.py b/third_party/coverage-3.7.1/coverage/misc.py
similarity index 93%
rename from third_party/coverage-3.6/coverage/misc.py
rename to third_party/coverage-3.7.1/coverage/misc.py
index ece8023bd451dd75ed99742c20581b92ce168208..0378173fcc3ddc92d00ca94d88d7ef3fec746a25 100644
--- a/third_party/coverage-3.6/coverage/misc.py
+++ b/third_party/coverage-3.7.1/coverage/misc.py
@@ -38,6 +38,8 @@ def format_lines(statements, lines):
     i = 0
     j = 0
     start = None
+    statements = sorted(statements)
+    lines = sorted(lines)
     while i < len(statements) and j < len(lines):
         if statements[i] == lines[j]:
             if start == None:
@@ -86,7 +88,7 @@ def bool_or_none(b):
 def join_regex(regexes):
     """Combine a list of regexes into one that matches any of them."""
     if len(regexes) > 1:
-        return "(" + ")|(".join(regexes) + ")"
+        return "|".join(["(%s)" % r for r in regexes])
     elif regexes:
         return regexes[0]
     else:
@@ -113,8 +115,10 @@ class Hasher(object):
         self.md5.update(to_bytes(str(type(v))))
         if isinstance(v, string_class):
             self.md5.update(to_bytes(v))
+        elif v is None:
+            pass
         elif isinstance(v, (int, float)):
-            self.update(str(v))
+            self.md5.update(to_bytes(str(v)))
         elif isinstance(v, (tuple, list)):
             for e in v:
                 self.update(e)
@@ -146,6 +150,10 @@ class NoSource(CoverageException):
     """We couldn't find the source for a module."""
     pass
 
+class NoCode(NoSource):
+    """We couldn't find any code at all."""
+    pass
+
 class NotPython(CoverageException):
     """A source file turned out not to be parsable Python."""
     pass