From 3473d9db20f0f3f312fa24fbf16440a1bef70fd2 Mon Sep 17 00:00:00 2001
From: Florent Daigniere <nextgens@freenetproject.org>
Date: Fri, 6 Sep 2024 13:56:32 +0200
Subject: [PATCH] fix #2996

(cherry picked from commit 61b444f00f900e7c41a5f7314f6a04be38e87b5e)
---
 optional/fetchmail/fetchmail.py     | 18 +++++++++++++++++-
 towncrier/newsfragments/2296.bugfix |  1 +
 2 files changed, 18 insertions(+), 1 deletion(-)
 create mode 100644 towncrier/newsfragments/2296.bugfix

diff --git a/optional/fetchmail/fetchmail.py b/optional/fetchmail/fetchmail.py
index 410ce4fb..8e26e82e 100755
--- a/optional/fetchmail/fetchmail.py
+++ b/optional/fetchmail/fetchmail.py
@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 
+import base64
 import time
 import os
 from pathlib import Path
@@ -32,6 +33,21 @@ poll "{host}" proto {protocol}  port {port}
     {lmtp}
 """
 
+def imaputf7encode(s):
+    """"Encode a string into RFC2060 aka IMAP UTF7"""
+    s=s.replace('&','&-')
+    iters=iter(s)
+    unipart=out=''
+    for c in s:
+        if 0x20<=ord(c)<=0x7f :
+            if unipart!='' :
+                out+='&'+base64.b64encode(unipart.encode('utf-16-be')).decode('ascii').rstrip('=')+'-'
+                unipart=''
+            out+=c
+        else : unipart+=c
+    if unipart!='' :
+        out+='&'+base64.b64encode(unipart.encode('utf-16-be')).decode('ascii').rstrip('=')+'-'
+    return out
 
 def escape_rc_string(arg):
     return "".join("\\x%2x" % ord(char) for char in arg)
@@ -54,7 +70,7 @@ def run(debug):
             options = "options antispam 501, 504, 550, 553, 554"
             options += " ssl" if fetch["tls"] else ""
             options += " keep" if fetch["keep"] else " fetchall"
-            folders = "folders %s" % ((','.join('"' + item + '"' for item in fetch['folders'])) if fetch['folders'] else '"INBOX"')
+            folders = "folders %s" % ((','.join('"' + imaputf7encode(item) + '"' for item in fetch['folders'])) if fetch['folders'] else '"INBOX"')
             fetchmailrc += RC_LINE.format(
                 user_email=escape_rc_string(fetch["user_email"]),
                 protocol=fetch["protocol"],
diff --git a/towncrier/newsfragments/2296.bugfix b/towncrier/newsfragments/2296.bugfix
new file mode 100644
index 00000000..493238ff
--- /dev/null
+++ b/towncrier/newsfragments/2296.bugfix
@@ -0,0 +1 @@
+Ensure fetchmail can deal with special characters in folder names