Support sizehint in StringIO.readlines, as documented.

diff --git a/Lib/StringIO.py b/Lib/StringIO.py
index 8efd7d8c48f9f733a3c6ad74c4b9905b2019ce0f..02eb7c8bec9483db482966f13adeeffd2d75e21b 100644 (file)
--- a/Lib/StringIO.py
+++ b/Lib/StringIO.py
@@ -91,11 +91,15 @@ class StringIO:
                r = self.buf[self.pos:newpos]
                self.pos = newpos
                return r
-       def readlines(self):
+       def readlines(self, sizehint = 0):
+               total = 0
                lines = []
                line = self.readline()
                while line:
                        lines.append(line)
+                       total += len(line)
+                       if 0 < sizehint <= total:
+                               break
                        line = self.readline()
                return lines
        def write(self, s):