From 7c1b25f7c1e9381fa4b96b4fc489e4bbbe065f02 Mon Sep 17 00:00:00 2001
From: JunWei Song <sungboss2004@gmail.com>
Date: Wed, 11 Sep 2019 23:04:12 +0800
Subject: [PATCH] bpo-36260: Add pitfalls to zipfile module documentation
 (#13378)
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* bpo-36260: Add pitfalls to zipfile module documentation

We saw vulnerability warning description (including zip bomb) in Doc/library/xml.rst file.
This gave us the idea of documentation improvement.

So, we moved a little bit forward :P
And the doc patch can be found (pr).

* fix trailing whitespace

* 📜 🤖  Added by blurb_it.

* Reformat text for consistency.

---
 Doc/library/zipfile.rst                       | 40 +++++++++++++++++++
 .../2019-06-04-09-29-00.bpo-36260.WrGuc-.rst  |  1 +
 2 files changed, 41 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Documentation/2019-06-04-09-29-00.bpo-36260.WrGuc-.rst

diff --git a/Doc/library/zipfile.rst b/Doc/library/zipfile.rst
index 6fb03a0..6fa0a28 100644
--- a/Doc/library/zipfile.rst
+++ b/Doc/library/zipfile.rst
@@ -730,5 +730,45 @@ Command-line options
 
    Test whether the zipfile is valid or not.
 
+Decompression pitfalls
+----------------------
+
+The extraction in zipfile module might fail due to some pitfalls listed below.
+
+From file itself
+~~~~~~~~~~~~~~~~
+
+Decompression may fail due to incorrect password / CRC checksum / ZIP format or
+unsupported compression method / decryption.
+
+File System limitations
+~~~~~~~~~~~~~~~~~~~~~~~
+
+Exceeding limitations on different file systems can cause decompression failed.
+Such as allowable characters in the directory entries, length of the file name,
+length of the pathname, size of a single file, and number of files, etc.
+
+Resources limitations
+~~~~~~~~~~~~~~~~~~~~~
+
+The lack of memory or disk volume would lead to decompression
+failed. For example, decompression bombs (aka `ZIP bomb`_)
+apply to zipfile library that can cause disk volume exhaustion.
+
+Interruption
+~~~~~~~~~~~~
+
+Interruption during the decompression, such as pressing control-C or killing the
+decompression process may result in incomplete decompression of the archive.
+
+Default behaviors of extraction
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Not knowing the default extraction behaviors
+can cause unexpected decompression results.
+For example, when extracting the same archive twice,
+it overwrites files without asking.
+
 
+.. _ZIP bomb: https://en.wikipedia.org/wiki/Zip_bomb
 .. _PKZIP Application Note: https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT
diff --git a/Misc/NEWS.d/next/Documentation/2019-06-04-09-29-00.bpo-36260.WrGuc-.rst b/Misc/NEWS.d/next/Documentation/2019-06-04-09-29-00.bpo-36260.WrGuc-.rst
new file mode 100644
index 0000000..9276516
--- /dev/null
+++ b/Misc/NEWS.d/next/Documentation/2019-06-04-09-29-00.bpo-36260.WrGuc-.rst
@@ -0,0 +1 @@
+Add decompression pitfalls to zipfile module documentation.
\ No newline at end of file
--
2.23.0
