feat: test patch for gmail/utf8

Dockerfile

@@ -2,12 +2,16 @@ FROM "alpine:3.23"
 LABEL maintainer="Cabillot Julien <dockerimages@cabillot.eu>"
 
 COPY entrypoint.sh /entrypoint.sh
+COPY patch.py /tmp/patch.py
 
 RUN apk add --no-cache offlineimap openssl && \
     adduser -D offlineimap && \
     # Force SECLEVEL=1 in imaplib2 to allow connecting to servers with weak DH keys (DH_KEY_TOO_SMALL)
     # This is required because OpenSSL 3.x in Alpine 3.23 defaults to SECLEVEL=2
-    sed -i 's/ctx = ssl.SSLContext(ssl_version)/ctx = ssl.SSLContext(ssl_version)\n                ctx.set_ciphers("DEFAULT:@SECLEVEL=1")/' /usr/lib/python3.*/site-packages/imaplib2/imaplib2.py
+    sed -i 's/ctx = ssl.SSLContext(ssl_version)/ctx = ssl.SSLContext(ssl_version)\n                ctx.set_ciphers("DEFAULT:@SECLEVEL=1")/' /usr/lib/python3.*/site-packages/imaplib2/imaplib2.py && \
+    # Patch offlineimap email generator bug for defective messages
+    python3 /tmp/patch.py && rm /tmp/patch.py
+
 COPY --chown=offlineimap offlineimaprc.*.tmpl /home/offlineimap/
 
 # Add Tini

patch.py

@@ -0,0 +1,26 @@
+import sys, os
+
+maildir_path = "/usr/lib/python3.12/site-packages/offlineimap/folder/Maildir.py"
+with open(maildir_path, "r") as f:
+    maildir = f.read()
+maildir = maildir.replace(
+    "fd.write(msg.as_bytes(policy=output_policy))",
+    "try:\n            fd.write(msg.as_bytes(policy=output_policy))\n        except UnicodeEncodeError:\n            fd.write(msg.as_string(policy=output_policy).encode('utf-8'))"
+)
+with open(maildir_path, "w") as f:
+    f.write(maildir)
+
+imap_path = "/usr/lib/python3.12/site-packages/offlineimap/folder/IMAP.py"
+with open(imap_path, "r") as f:
+    imap_py = f.read()
+
+imap_patch = """
+def get_msg_bytes(msg, policy):
+    try:
+        return msg.as_bytes(policy=policy)
+    except UnicodeEncodeError:
+        return msg.as_string(policy=policy).encode('utf-8')
+"""
+imap_py = imap_patch + imap_py.replace("msg.as_bytes(policy=output_policy)", "get_msg_bytes(msg, output_policy)")
+with open(imap_path, "w") as f:
+    f.write(imap_py)