Error from nil MXC argument to ement--media-request

[phil-s]

I encountered this just now:

Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  string-match("mxc://\\([^/]+\\)/\\([^z-a]+\\)" nil)
  ement--mxc-to-endpoint(nil)
  ement--media-request(nil #s(ement-session ...) :then #f(...) :else #f(...) :queue #s(plz-queue ...) :authenticatedp t)
  ement-room--image-download(...)
  ement-room--format-m.image(...)

In a bit more detail:

Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  string-match("mxc://\\([^/]+\\)/\\([^z-a]+\\)" nil)
  ement--mxc-to-endpoint(nil)
  ement--media-request(nil #s(ement-session :user ... :server ... :token "..." :transaction-id 2562682986 :rooms ... :next-batch "s5356622809_757284974_17004110_3197373295_3474708229_261644646_1399661551_11030818304_0_360008" :device-id nil :initial-device-display-name nil :has-synced-p t :account-data ... :events #<hash-table equal 3729/6144 0x1e48b9de51f8 ...>) :then #f(compiled-function (&rest args2) #<bytecode -0x57dd47ee68ade1c>) :else #f(compiled-function (plz-error) "Handle PLZ-ERROR for a failed request to download an image." #<bytecode -0x25c6aed1139c286>) :queue #s(plz-queue :limit 5 :active nil :requests nil :canceled-p nil :first-active nil :last-active nil :first-request nil :last-request nil :finally nil) :authenticatedp t)
  ement-room--image-download(#s(ement-event :id "$RGFAXsXzE8GNS8rePT0mKwMhA9Fp4zwF2xDwSMeeFQY" :sender ... :content ... :origin-server-ts 1729344217155 :type "m.room.message" :unsigned ... :state-key nil :receipts nil :local nil) #s(ement-session :user ... :server ... :token "..." :transaction-id 2562682986 :rooms ... :next-batch "s5356622809_757284974_17004110_3197373295_3474708229_261644646_1399661551_11030818304_0_360008" :device-id nil :initial-device-display-name nil :has-synced-p t :account-data ... :events #<hash-table equal 3729/6144 0x1e48b9de51f8 ...>) :then #f(compiled-function (&rest args2) #<bytecode -0x57dd47ee68ade1c>) :else #f(compiled-function (plz-error) "Handle PLZ-ERROR for a failed request to download an image." #<bytecode -0x25c6aed1139c286>))
  ement-room--format-m.image(#s(ement-event :id "$RGFAXsXzE8GNS8rePT0mKwMhA9Fp4zwF2xDwSMeeFQY" :sender ... :content ... :origin-server-ts 1729344217155 :type "m.room.message" :unsigned ... :state-key nil :receipts nil :local nil) #s(ement-session :user ... :server ... :token "..." :transaction-id 2562682986 :rooms ... :next-batch "s5356622809_757284974_17004110_3197373295_3474708229_261644646_1399661551_11030818304_0_360008" :device-id nil :initial-device-display-name nil :has-synced-p t :account-data ... :events #<hash-table equal 3729/6144 0x1e48b9de51f8 ...>))

This was from the #emacs:matrix.org room, so you might be able to replicate it. I get the error every time I kill the room buffer and then revisit that room. My current session has history for that room back to 2024-09-27 (Friday).

In addition I was seeing (ement-api-error "404: Event not found.") which may be the reason behind the initial error.

I tried the following code change, after which I only get the 404 error.

modified   ement-room.el
@@ -5706,8 +5706,9 @@ ement-room--image-download
   (declare (indent defun))
   (pcase-let* (((cl-struct ement-event content) event)
                ((map ('url mxc)) content))
-    (ement--media-request mxc session :then then :else else
-      :queue ement-images-queue :authenticatedp authenticatedp)))
+    (when mxc
+      (ement--media-request mxc session :then then :else else
+        :queue ement-images-queue :authenticatedp authenticatedp))))
 
 (defun ement-room--format-m.image (event session)
   "Return \"m.image\" EVENT on SESSION formatted as a string.

[phil-s]

(pp-eval-expression '(gethash "$RGFAXsXzE8GNS8rePT0mKwMhA9Fp4zwF2xDwSMeeFQY" (ement-session-events ement-session))):

#s(ement-event "$RGFAXsXzE8GNS8rePT0mKwMhA9Fp4zwF2xDwSMeeFQY"
	       #s(ement-user "@tusharhero:envs.net" "tusharhero" nil
			     "#5640d4" nil nil nil nil)
	       ((body . "JPEG_20241019_185233_3350740080818014340.jpg")
		(file
		 (hashes
		  (sha256
		   . "E8Fw3zmAlHy4RiLrU2V8Z2C4U/YgNlu9ethieYs3CIQ"))
		 (iv . "wU8P9278r9WhMmpCjOp/Sg")
		 (key (alg . "A256CTR") (ext . t)
		      (k
		       . "Coe7KTfTEboqUrGwy4YuSuzq5GX20ptzfJbg9tyUhBk")
		      (key_ops . ["encrypt" "decrypt"]) (kty . "oct"))
		 (mimetype . "image/jpeg")
		 (url
		  . "mxc://envs.net/4feae4c2af59b8875dcf8cc463a389c73207ec3e1847629421142343680")
		 (v . "v2"))
		(filename
		 . "JPEG_20241019_185233_3350740080818014340.jpg")
		(info (h . 1600) (mimetype . "image/jpeg")
		      (size . 56749)
		      (thumbnail_file
		       (hashes
			(sha256
			 . "SEd2oZC9d6/mmQuQNND20jreVkdwt6nDsZ3cljKtg8E"))
		       (iv . "oHEmOq+17t0nI0U8rxYimQ")
		       (key (alg . "A256CTR") (ext . t)
			    (k
			     . "sqKMoVDV-Z4RzTLbGJyRfMFC8QsAHVaDIaUHWZOK6lE")
			    (key_ops . ["encrypt" "decrypt"])
			    (kty . "oct"))
		       (mimetype . "image/jpeg")
		       (url
			. "mxc://envs.net/db05a0be5145424afe4166510d813e79149cb7991847629422476132352")
		       (v . "v2"))
		      (thumbnail_info (h . 800)
				      (mimetype . "image/jpeg")
				      (size . 19692) (w . 369)
				      (xyz.amorgan.blurhash
				       . "K33bgoxuWBxut7Rj~qxuWB"))
		      (w . 738)
		      (xyz.amorgan.blurhash . "K33uo}xuWB%2xaRj~qxuWB"))
		(msgtype . "m.image"))
	       1729344217155 "m.room.message" ((membership . "join"))
	       nil nil nil)

[alphapapa]

Thanks, Phil. Probably just need to adjust the ELSE handler to allow 404s and other HTTP errors to be handled by displaying an error.