Use overlay instead of text prop to hide ERC's prompt

* lisp/erc/erc-backend.el (erc--hidden-prompt-overlay):
New variable, a buffer-local handle for the prompt overlay.
(erc--reveal-prompt): Delete overlay instead of text prop.
(erc--conceal-prompt): Add overlay instead of text prop.
(erc--unhide-prompt): Run `erc--refresh-prompt-hook' after revealing.
(erc--hide-prompt): Run `erc--refresh-prompt-hook' after hiding.
* lisp/erc/erc-stamp.el (erc-stamp--adjust-margin): Attempt a more
accurate estimate of the prompt's width in columns when initially
setting left-margin.
(erc-stamp--skip-left-margin-prompt-p): New variable to inhibit normal
behavior of displaying prompt in left margin.
(erc-stamp--display-margin-mode): Allow opting out of
prompt-in-left-margin behavior.
(erc--reveal-prompt): Delete unneeded method implementation.
(erc--conceal-prompt): Put overlay in margin.
* test/lisp/erc/erc-tests.el (erc-hide-prompt): Use
`get-char-property' instead of `get-text-property' in order to
accommodate overlay-based prompt hiding.  (Bug#51082)

1 files changed, 23 insertions, 23 deletions

diff --git a/test/lisp/erc/erc-tests.el b/test/lisp/erc/erc-tests.el
index 8c85f37dfe5..980928aceac 100644
--- a/test/lisp/erc/erc-tests.el
+++ b/test/lisp/erc/erc-tests.el
@@ -187,101 +187,101 @@
       (with-current-buffer "ServNet"
         (should (= (point) erc-insert-marker))
         (erc--hide-prompt erc-server-process)
-        (should (string= ">" (get-text-property (point) 'display))))
+        (should (string= ">" (get-char-property (point) 'display))))
 
       (with-current-buffer "#chan"
         (goto-char erc-insert-marker)
-        (should (string= ">" (get-text-property (point) 'display)))
+        (should (string= ">" (get-char-property (point) 'display)))
         (should (memq #'erc--unhide-prompt-on-self-insert pre-command-hook))
         (goto-char erc-input-marker)
         (ert-simulate-command '(self-insert-command 1 ?/))
         (goto-char erc-insert-marker)
-        (should-not (get-text-property (point) 'display))
+        (should-not (get-char-property (point) 'display))
         (should-not (memq #'erc--unhide-prompt-on-self-insert
                           pre-command-hook)))
 
       (with-current-buffer "bob"
         (goto-char erc-insert-marker)
-        (should (string= ">" (get-text-property (point) 'display)))
+        (should (string= ">" (get-char-property (point) 'display)))
         (should (memq #'erc--unhide-prompt-on-self-insert pre-command-hook))
         (goto-char erc-input-marker)
         (ert-simulate-command '(self-insert-command 1 ?/))
         (goto-char erc-insert-marker)
-        (should-not (get-text-property (point) 'display))
+        (should-not (get-char-property (point) 'display))
         (should-not (memq #'erc--unhide-prompt-on-self-insert
                           pre-command-hook)))
 
       (with-current-buffer "ServNet"
-        (should (get-text-property erc-insert-marker 'display))
+        (should (get-char-property erc-insert-marker 'display))
         (should (memq #'erc--unhide-prompt-on-self-insert pre-command-hook))
         (erc--unhide-prompt)
         (should-not (memq #'erc--unhide-prompt-on-self-insert
                           pre-command-hook))
-        (should-not (get-text-property erc-insert-marker 'display))))
+        (should-not (get-char-property erc-insert-marker 'display))))
 
     (ert-info ("Value: server")
       (setq erc-hide-prompt '(server))
       (with-current-buffer "ServNet"
         (erc--hide-prompt erc-server-process)
         (should (eq (get-text-property erc-insert-marker 'erc-prompt) 'hidden))
-        (should (string= ">" (get-text-property erc-insert-marker 'display))))
+        (should (string= ">" (get-char-property erc-insert-marker 'display))))
 
       (with-current-buffer "#chan"
-        (should-not (get-text-property erc-insert-marker 'display)))
+        (should-not (get-char-property erc-insert-marker 'display)))
 
       (with-current-buffer "bob"
-        (should-not (get-text-property erc-insert-marker 'display)))
+        (should-not (get-char-property erc-insert-marker 'display)))
 
       (with-current-buffer "ServNet"
         (erc--unhide-prompt)
         (should (eq (get-text-property erc-insert-marker 'erc-prompt) t))
-        (should-not (get-text-property erc-insert-marker 'display))))
+        (should-not (get-char-property erc-insert-marker 'display))))
 
     (ert-info ("Value: channel")
       (setq erc-hide-prompt '(channel))
       (with-current-buffer "ServNet"
         (erc--hide-prompt erc-server-process)
-        (should-not (get-text-property erc-insert-marker 'display)))
+        (should-not (get-char-property erc-insert-marker 'display)))
 
       (with-current-buffer "bob"
-        (should-not (get-text-property erc-insert-marker 'display)))
+        (should-not (get-char-property erc-insert-marker 'display)))
 
       (with-current-buffer "#chan"
-        (should (string= ">" (get-text-property erc-insert-marker 'display)))
+        (should (string= ">" (get-char-property erc-insert-marker 'display)))
         (should (eq (get-text-property erc-insert-marker 'erc-prompt) 'hidden))
         (erc--unhide-prompt)
         (should (eq (get-text-property erc-insert-marker 'erc-prompt) t))
-        (should-not (get-text-property erc-insert-marker 'display))))
+        (should-not (get-char-property erc-insert-marker 'display))))
 
     (ert-info ("Value: query")
       (setq erc-hide-prompt '(query))
       (with-current-buffer "ServNet"
         (erc--hide-prompt erc-server-process)
-        (should-not (get-text-property erc-insert-marker 'display)))
+        (should-not (get-char-property erc-insert-marker 'display)))
 
       (with-current-buffer "bob"
-        (should (string= ">" (get-text-property erc-insert-marker 'display)))
+        (should (string= ">" (get-char-property erc-insert-marker 'display)))
         (should (eq (get-text-property erc-insert-marker 'erc-prompt) 'hidden))
         (erc--unhide-prompt)
         (should (eq (get-text-property erc-insert-marker 'erc-prompt) t))
-        (should-not (get-text-property erc-insert-marker 'display)))
+        (should-not (get-char-property erc-insert-marker 'display)))
 
       (with-current-buffer "#chan"
-        (should-not (get-text-property erc-insert-marker 'display))))
+        (should-not (get-char-property erc-insert-marker 'display))))
 
     (ert-info ("Value: nil")
       (setq erc-hide-prompt nil)
       (with-current-buffer "ServNet"
         (erc--hide-prompt erc-server-process)
-        (should-not (get-text-property erc-insert-marker 'display)))
+        (should-not (get-char-property erc-insert-marker 'display)))
 
       (with-current-buffer "bob"
-        (should-not (get-text-property erc-insert-marker 'display)))
+        (should-not (get-char-property erc-insert-marker 'display)))
 
       (with-current-buffer "#chan"
-        (should-not (get-text-property erc-insert-marker 'display))
+        (should-not (get-char-property erc-insert-marker 'display))
         (erc--unhide-prompt) ; won't blow up when prompt already showing
-        (should-not (get-text-property erc-insert-marker 'display))))
+        (should-not (get-char-property erc-insert-marker 'display))))
 
     (when noninteractive
       (kill-buffer "#chan")