Issue #8260: The read(), readline() and readlines() methods of

codecs.StreamReader returned incomplete data when were called after
readline() or read(size).  Based on patch by Amaury Forgeot d'Arc.

1 files changed, 6 insertions, 7 deletions

diff --git a/Lib/codecs.py b/Lib/codecs.py
index 2e2e755..c2065da 100644
--- a/Lib/codecs.py
+++ b/Lib/codecs.py
@@ -475,15 +475,12 @@ class StreamReader(Codec):
         # read until we get the required number of characters (if available)
         while True:
             # can the request be satisfied from the character buffer?
-            if chars < 0:
-                if size < 0:
-                    if self.charbuffer:
-                        break
-                elif len(self.charbuffer) >= size:
-                    break
-            else:
+            if chars >= 0:
                 if len(self.charbuffer) >= chars:
                     break
+            elif size >= 0:
+                if len(self.charbuffer) >= size:
+                    break
             # we need more data
             if size < 0:
                 newdata = self.stream.read()
@@ -491,6 +488,8 @@ class StreamReader(Codec):
                 newdata = self.stream.read(size)
             # decode bytes (those remaining from the last call included)
             data = self.bytebuffer + newdata
+            if not data:
+                break
             try:
                 newchars, decodedbytes = self.decode(data, self.errors)
             except UnicodeDecodeError as exc: