fix: list deduplicated attachments on every Communication

cloud_storage/__init__.py

@@ -4,8 +4,11 @@
 __version__ = "15.7.4"
 
 
+import json
+
 import frappe
 import frappe.desk.form.load
+from frappe.core.doctype.communication.communication import Communication
 from frappe.core.doctype.file import file as file_module
 from frappe.query_builder import DocType
 
@@ -41,3 +44,57 @@ def patched_get_attachments(dt, dn):
 
 
 frappe.desk.form.load.get_attachments = patched_get_attachments
+
+
+ATTACHMENT_FIELDS = ["name", "file_name", "file_url", "is_private"]
+
+
+def get_files_for_document(dt, dn, fields=ATTACHMENT_FIELDS):
+	"""All File rows that belong to a document, by `attached_to_*` or by File Association.
+	"""
+	files = frappe.get_all(
+		"File", fields=fields, filters={"attached_to_doctype": dt, "attached_to_name": str(dn)}
+	)
+	if "cloud_storage" not in frappe.get_installed_apps():
+		return files
+
+	seen = {f.name for f in files}
+	linked = frappe.get_all(
+		"File Association", filters={"link_doctype": dt, "link_name": str(dn)}, pluck="parent"
+	)
+	missing = [name for name in set(linked) if name not in seen]
+	if missing:
+		files += frappe.get_all("File", fields=fields, filters={"name": ["in", missing]})
+	return files
+
+
+def patched_get_communications(doctype, name, start=0, limit=20):
+	"""
+	HASH: 48366c6ecbad44ed24e6d02bdd8f8f189ce58927
+	REPO: https://github.com/frappe/frappe
+	PATH: frappe/desk/form/load.py
+	METHOD: _get_communications
+
+	Core looks attachments up by `attached_to_*` only, so when the same files are emailed
+	from one document several times only the last email lists them in the timeline.
+	"""
+	communications = frappe.desk.form.load.get_communication_data(doctype, name, start, limit)
+	for c in communications:
+		if c.communication_type in ("Communication", "Automated Message"):
+			c.attachments = json.dumps(get_files_for_document("Communication", c.name))
+
+	return communications
+
+
+def patched_communication_get_attachments(self):
+	"""
+	HASH: 48366c6ecbad44ed24e6d02bdd8f8f189ce58927
+	REPO: https://github.com/frappe/frappe
+	PATH: frappe/core/doctype/communication/communication.py
+	METHOD: get_attachments
+	"""
+	return get_files_for_document(self.DOCTYPE, self.name)
+
+
+frappe.desk.form.load._get_communications = patched_get_communications
+Communication.get_attachments = patched_communication_get_attachments

cloud_storage/tests/test_communication_attachments.py

@@ -0,0 +1,88 @@
+# Copyright (c) 2026, AgriTheory and contributors
+# For license information, please see license.txt
+
+import json
+from io import BytesIO
+
+import frappe
+import pytest
+
+from cloud_storage import get_files_for_document
+
+pytestmark = pytest.mark.usefixtures("mocked_s3_client")
+
+
+def make_communication(subject):
+	return frappe.get_doc(
+		{
+			"doctype": "Communication",
+			"communication_type": "Communication",
+			"communication_medium": "Email",
+			"sent_or_received": "Sent",
+			"status": "Linked",
+			"subject": subject,
+			"sender": "Administrator",
+			"recipients": "supplier@example.com",
+			"content": subject,
+			"reference_doctype": "Role",
+			"reference_name": "System Manager",
+		}
+	).insert(ignore_permissions=True)
+
+
+def attach(communication, file_name, content):
+	# what frappe.core.doctype.communication.email.add_attachments does for a sent email
+	return frappe.get_doc(
+		{
+			"doctype": "File",
+			"file_name": file_name,
+			"attached_to_doctype": "Communication",
+			"attached_to_name": communication.name,
+			"folder": "Home/Attachments",
+			"content": content,
+			"decode": False,
+			"is_private": 1,
+		}
+	).save(ignore_permissions=True)
+
+
+def test_same_attachment_emailed_twice_is_listed_on_both_communications():
+	"""The second email's File is merged into the first one and steals `attached_to`, so core's
+	`attached_to`-based lookups list the attachment on one Communication only."""
+	from PIL import Image
+
+	frappe.set_user("Administrator")
+	buffer = BytesIO()
+	Image.new("RGB", (5, 9), (200, 30, 90)).save(buffer, format="PNG")
+	content = buffer.getvalue()
+
+	first = make_communication("RFQ to supplier 1")
+	second = make_communication("RFQ to supplier 2")
+	try:
+		attach(first, "drawing.png", content)
+		attach(second, "drawing.png", content)
+
+		# one physical File survives, now attached_to the second Communication
+		owners = frappe.get_all(
+			"File", filters={"file_name": "drawing.png"}, pluck="attached_to_name"
+		)
+		assert owners == [second.name]
+
+		for comm in (first, second):
+			files = get_files_for_document("Communication", comm.name)
+			assert [f.file_name for f in files] == ["drawing.png"]
+			assert [f.file_name for f in comm.get_attachments()] == ["drawing.png"]
+
+		# what the form timeline renders for each email
+		timeline = {
+			c.name: json.loads(c.attachments)
+			for c in frappe.desk.form.load._get_communications("Role", "System Manager", limit=50)
+			if c.name in (first.name, second.name)
+		}
+		assert len(timeline) == 2
+		for files in timeline.values():
+			assert len(files) == 1
+			assert "?key=" in files[0]["file_url"]
+	finally:
+		for comm in (first, second):
+			frappe.delete_doc("Communication", comm.name, ignore_permissions=True, force=True)