4 files changed, 13 insertions, 5 deletions

diff --git a/lisp/net/sasl.el b/lisp/net/sasl.el
index 289e867e672..3f805237683 100644
--- a/lisp/net/sasl.el
+++ b/lisp/net/sasl.el
@@ -50,8 +50,7 @@
 
 (defvar sasl-unique-id-function #'sasl-unique-id-function)
 
-(put 'sasl-error 'error-message "SASL error")
-(put 'sasl-error 'error-conditions '(sasl-error error))
+(define-error 'sasl-error "SASL error")
 
 (defun sasl-error (datum)
   (signal 'sasl-error (list datum)))
diff --git a/lisp/net/soap-client.el b/lisp/net/soap-client.el
index beebe9b4445..f6d2ba229e5 100644
--- a/lisp/net/soap-client.el
+++ b/lisp/net/soap-client.el
@@ -2886,7 +2886,7 @@ decode function to perform the actual decoding."
 
 ;;;; Soap Envelope parsing
 
-(if (fboundp 'define-error)
+(if (fboundp 'define-error)             ;Emacs-24.4
     (define-error 'soap-error "SOAP error")
   ;; Support Emacs<24.4 that do not have define-error, so
   ;; that soap-client can remain unchanged in GNU ELPA.
diff --git a/lisp/net/tramp-compat.el b/lisp/net/tramp-compat.el
index f975457d4df..ecc6fe96855 100644
--- a/lisp/net/tramp-compat.el
+++ b/lisp/net/tramp-compat.el
@@ -102,14 +102,19 @@ Add the extension of F, if existing."
     tramp-temp-name-prefix tramp-compat-temporary-file-directory)
    dir-flag (file-name-extension f t)))
 
+(defalias 'tramp-error-type-p
+  (if (fboundp 'error-type-p)           ;Emacs-31
+      #'error-type-p
+    (lambda (symbol) (get symbol 'error-conditions))))
+
 ;; `permission-denied' is introduced in Emacs 29.1.
 (defconst tramp-permission-denied
-  (if (get 'permission-denied 'error-conditions) 'permission-denied 'file-error)
+  (if (tramp-error-type-p 'permission-denied) 'permission-denied 'file-error)
   "The error symbol for the `permission-denied' error.")
 
 (defsubst tramp-compat-permission-denied (vec file)
   "Emit the `permission-denied' error."
-  (if (get 'permission-denied 'error-conditions)
+  (if (tramp-error-type-p 'permission-denied)
       (tramp-error vec tramp-permission-denied file)
     (tramp-error vec tramp-permission-denied "Permission denied: %s" file)))
 
diff --git a/lisp/net/tramp-message.el b/lisp/net/tramp-message.el
index 7b405061ba8..37628e2f001 100644
--- a/lisp/net/tramp-message.el
+++ b/lisp/net/tramp-message.el
@@ -398,8 +398,12 @@ FMT-STRING and ARGUMENTS."
      vec-or-proc 1 "%s"
      (error-message-string
       (list signal
+            ;; FIXME: Looks redundant since `error-message-string'
+            ;; already uses the `error-message' property of `signal'!
             (get signal 'error-message)
             (apply #'format-message fmt-string arguments))))
+    ;; FIXME: This doesn't look right: ELisp code should be able to rely on
+    ;; the "shape" of the list based on the type of the signal.
     (signal signal (list (substring-no-properties
                           (apply #'format-message fmt-string arguments))))))