From 9068c336f4a652766cf5c5c0c40ea2351ee7c9fe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?K=C3=A9vin=20Commaille?=
 <76261501+zecakeh@users.noreply.github.com>
Date: Fri, 8 Mar 2024 03:13:38 +0100
Subject: [PATCH] Clarify that sdpMid and sdpMLineIndex are not required in
 `m.call.candidates` (#1742)
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* Convert m.call.candidates schema to YAML

Signed-off-by: Kévin Commaille <zecakeh@tedomum.fr>

* Clarify that sdpMid and sdpMLineIndex are not required in `m.call.candidates`

MSC2746, merged in v1.17,
introduced the end-of-candidates candidate,
where only the `candidate` property is set to an empty string.

Besides, the [WebRTC specification](https://www.w3.org/TR/webrtc/)
says that only one of those fields is required in a normal candidate.

Signed-off-by: Kévin Commaille <zecakeh@tedomum.fr>

* Add changelog

Signed-off-by: Kévin Commaille <zecakeh@tedomum.fr>

* Link to the "End-of-candidates" section, and clarify what "empty" means

Signed-off-by: Kévin Commaille <zecakeh@tedomum.fr>

---------

Signed-off-by: Kévin Commaille <zecakeh@tedomum.fr>
---
 .../newsfragments/1742.clarification          |  1 +
 .../schema/m.call.candidates.yaml             | 94 ++++++++++---------
 2 files changed, 50 insertions(+), 45 deletions(-)
 create mode 100644 changelogs/client_server/newsfragments/1742.clarification

diff --git a/changelogs/client_server/newsfragments/1742.clarification b/changelogs/client_server/newsfragments/1742.clarification
new file mode 100644
index 00000000..84f21b9e
--- /dev/null
+++ b/changelogs/client_server/newsfragments/1742.clarification
@@ -0,0 +1 @@
+Clarify that `sdpMid` and `sdpMLineIndex` are not required in `m.call.candidates`.
\ No newline at end of file
diff --git a/data/event-schemas/schema/m.call.candidates.yaml b/data/event-schemas/schema/m.call.candidates.yaml
index 6aa16229..d43ede98 100644
--- a/data/event-schemas/schema/m.call.candidates.yaml
+++ b/data/event-schemas/schema/m.call.candidates.yaml
@@ -1,45 +1,49 @@
-{
-    "type": "object",
-    "description": "This event is sent by callers after sending an invite and by the callee after answering. Its purpose is to give the other party additional ICE candidates to try using to communicate.",
-    "allOf": [{
-        "$ref": "core-event-schema/room_event.yaml"
-    }],
-    "properties": {
-        "content": {
-            "type": "object",
-            "allOf": [{
-                "$ref": "core-event-schema/call_event.yaml"
-            }],
-            "properties": {
-                "candidates": {
-                    "type": "array",
-                    "description": "Array of objects describing the candidates.",
-                    "items": {
-                        "type": "object",
-                        "title": "Candidate",
-                        "properties": {
-                            "sdpMid": {
-                                "type": "string",
-                                "description": "The SDP media type this candidate is intended for."
-                            },
-                            "sdpMLineIndex": {
-                                "type": "number",
-                                "description": "The index of the SDP 'm' line this candidate is intended for."
-                            },
-                            "candidate": {
-                                "type": "string",
-                                "description": "The SDP 'a' line of the candidate."
-                            }
-                        },
-                        "required": ["candidate", "sdpMLineIndex", "sdpMid"]
-                    }
-                }
-            },
-            "required": ["candidates"]
-        },
-        "type": {
-            "type": "string",
-            "enum": ["m.call.candidates"]
-        }
-    }
-}
+type: object
+description: |-
+  This event is sent by callers after sending an invite and by the callee after
+  answering. Its purpose is to give the other party additional ICE candidates to
+  try using to communicate.
+allOf:
+  - $ref: core-event-schema/room_event.yaml
+properties:
+  content:
+    type: object
+    allOf:
+      - $ref: core-event-schema/call_event.yaml
+    properties:
+      candidates:
+        type: array
+        description: Array of objects describing the candidates.
+        items:
+          type: object
+          title: Candidate
+          properties:
+            sdpMid:
+              type: string
+              description: |-
+                The SDP media type this candidate is intended for.
+
+                At least one of `sdpMid` or `sdpMLineIndex` is required, unless
+                this an end-of-candidates candidate.
+            sdpMLineIndex:
+              type: number
+              description: |-
+                The index of the SDP 'm' line this candidate is intended for.
+
+                At least one of `sdpMid` or `sdpMLineIndex` is required, unless
+                this an end-of-candidates candidate.
+            candidate:
+              type: string
+              description: |-
+                The SDP 'a' line of the candidate.
+
+                If this is an [end-of-candidates](/client-server-api/#end-of-candidates)
+                candidate, this is the empty string.
+          required:
+            - candidate
+    required:
+      - candidates
+  type:
+    type: string
+    enum:
+      - m.call.candidates
\ No newline at end of file