Ignore permalink_prefix when serializing Markdown

fixes element-hq/element-web/issues/26002

During serialization of messages, pills were wrongfully serialized to a URL
starting with `permalink_prefix`. This is against the Spec (which mandates
https://matrix.to/#/ links) and the resulting pills were not recognized as
pills in other clients.

[Spec-Appendendix concerning matrix.to link](https://spec.matrix.org/v1.8/appendices/#matrixto-navigation)

src/editor/serialize.ts

@@ -37,15 +37,15 @@ export function mdSerialize(model: EditorModel): string {
             case Type.AtRoomPill:
                 return html + part.text;
             case Type.RoomPill: {
-                const url = makeGenericPermalink(part.resourceId);
+                const url = makeGenericPermalink(part.resourceId, true);
                 // Escape square brackets and backslashes
                 // Here we use the resourceId for compatibility with non-rich text clients
                 // See https://github.com/vector-im/element-web/issues/16660
                 const title = part.resourceId.replace(/[[\\\]]/g, (c) => "\\" + c);
                 return html + `[${title}](${url})`;
             }
             case Type.UserPill: {
-                const url = makeGenericPermalink(part.resourceId);
+                const url = makeGenericPermalink(part.resourceId, true);
                 // Escape square brackets and backslashes; convert newlines to HTML
                 const title = part.text.replace(/[[\\\]]/g, (c) => "\\" + c).replace(/\n/g, "<br>");
                 return html + `[${title}](${url})`;

src/utils/permalinks/ElementPermalinkConstructor.ts

@@ -31,23 +31,32 @@ export default class ElementPermalinkConstructor extends PermalinkConstructor {
         }
     }
 
-    public forEvent(roomId: string, eventId: string, serverCandidates: string[]): string {
+    public forEvent(roomId: string, eventId: string, serverCandidates: string[], ispill = false): string {
+        if(ispill) {
+            return `https://matrix.to/#/${roomId}/${eventId}${this.encodeServerCandidates(serverCandidates)}`;
+        }
         return `${this.elementUrl}/#/room/${roomId}/${eventId}${this.encodeServerCandidates(serverCandidates)}`;
     }
 
-    public forRoom(roomIdOrAlias: string, serverCandidates?: string[]): string {
+    public forRoom(roomIdOrAlias: string, serverCandidates?: string[], ispill = false): string {
+        if(ispill) {
+            return `https://matrix.to/#/${roomIdOrAlias}${this.encodeServerCandidates(serverCandidates)}`;
+        }
         return `${this.elementUrl}/#/room/${roomIdOrAlias}${this.encodeServerCandidates(serverCandidates)}`;
     }
 
-    public forUser(userId: string): string {
+    public forUser(userId: string, ispill = false): string {
+        if(ispill) {
+            return `https://matrix.to/#/${userId}`;
+        }
         return `${this.elementUrl}/#/user/${userId}`;
     }
 
-    public forEntity(entityId: string): string {
+    public forEntity(entityId: string, ispill = false): string {
         if (entityId[0] === "!" || entityId[0] === "#") {
-            return this.forRoom(entityId);
+            return this.forRoom(entityId, [], ispill);
         } else if (entityId[0] === "@") {
-            return this.forUser(entityId);
+            return this.forUser(entityId, ispill);
         } else throw new Error("Unrecognized entity");
     }
 

src/utils/permalinks/PermalinkConstructor.ts

@@ -19,19 +19,19 @@ limitations under the License.
  * TODO: Convert this to a real TypeScript interface
  */
 export default class PermalinkConstructor {
-    public forEvent(roomId: string, eventId: string, serverCandidates: string[] = []): string {
+    public forEvent(roomId: string, eventId: string, serverCandidates: string[] = [], ispill = false): string {
         throw new Error("Not implemented");
     }
 
-    public forRoom(roomIdOrAlias: string, serverCandidates: string[] = []): string {
+    public forRoom(roomIdOrAlias: string, serverCandidates: string[] = [], ispill = false): string {
         throw new Error("Not implemented");
     }
 
-    public forUser(userId: string): string {
+    public forUser(userId: string, ispill = false): string {
         throw new Error("Not implemented");
     }
 
-    public forEntity(entityId: string): string {
+    public forEntity(entityId: string, ispill = false): string {
         throw new Error("Not implemented");
     }
 

src/utils/permalinks/Permalinks.ts

@@ -269,26 +269,26 @@ export class RoomPermalinkCreator {
     };
 }
 
-export function makeGenericPermalink(entityId: string): string {
-    return getPermalinkConstructor().forEntity(entityId);
+export function makeGenericPermalink(entityId: string, ispill = false): string {
+    return getPermalinkConstructor().forEntity(entityId, ispill);
 }
 
-export function makeUserPermalink(userId: string): string {
+export function makeUserPermalink(userId: string, ispill = false): string {
     return getPermalinkConstructor().forUser(userId);
 }
 
-export function makeRoomPermalink(matrixClient: MatrixClient, roomId: string): string {
+export function makeRoomPermalink(matrixClient: MatrixClient, roomId: string, ispill = false): string {
     if (!roomId) {
         throw new Error("can't permalink a falsy roomId");
     }
 
     // If the roomId isn't actually a room ID, don't try to list the servers.
     // Aliases are already routable, and don't need extra information.
-    if (roomId[0] !== "!") return getPermalinkConstructor().forRoom(roomId, []);
+    if (roomId[0] !== "!") return getPermalinkConstructor().forRoom(roomId, [], ispill);
 
     const room = matrixClient.getRoom(roomId);
     if (!room) {
-        return getPermalinkConstructor().forRoom(roomId, []);
+        return getPermalinkConstructor().forRoom(roomId, [], ispill);
     }
     const permalinkCreator = new RoomPermalinkCreator(room);
     permalinkCreator.load();