bpo-26185: Fix repr() on empty ZipInfo object (#13441)

* bpo-26185: Fix repr() on empty ZipInfo object

It was failing on AttributeError due to inexistant
but required attributes file_size and compress_size.
They are now initialized to 0 in ZipInfo.__init__().

* Remove useless hasattr() in ZipInfo._open_to_write()

* Completely remove file_size setting in _open_to_write().

1 files changed, 3 insertions, 5 deletions

diff --git a/Lib/zipfile.py b/Lib/zipfile.py
index dfd0907..c2c5b6a 100644
--- a/Lib/zipfile.py
+++ b/Lib/zipfile.py
@@ -376,11 +376,11 @@ class ZipInfo (object):
         self.volume = 0                 # Volume number of file header
         self.internal_attr = 0          # Internal attributes
         self.external_attr = 0          # External file attributes
+        self.compress_size = 0          # Size of the compressed file
+        self.file_size = 0              # Size of the uncompressed file
         # Other attributes are set by class ZipFile:
         # header_offset         Byte offset to the file header
         # CRC                   CRC-32 of the uncompressed file
-        # compress_size         Size of the compressed file
-        # file_size             Size of the uncompressed file
 
     def __repr__(self):
         result = ['<%s filename=%r' % (self.__class__.__name__, self.filename)]
@@ -1564,9 +1564,7 @@ class ZipFile:
                              "another write handle open on it. "
                              "Close the first handle before opening another.")
 
-        # Sizes and CRC are overwritten with correct data after processing the file
-        if not hasattr(zinfo, 'file_size'):
-            zinfo.file_size = 0
+        # Size and CRC are overwritten with correct data after processing the file
         zinfo.compress_size = 0
         zinfo.CRC = 0