From d4574ee392b9a8c537bec895be37468b600c25ac Mon Sep 17 00:00:00 2001
From: sm2n <theone@sm2n.ca>
Date: Fri, 12 Mar 2021 00:48:14 -0500
Subject: [PATCH] Fix eldoc-box-only-multi-line behavior

Prior to this change, single line eldoc messages were just ignored
completely when eldoc-box-only-multi-line was non-nil, though they
should have been displayed in the minibuffer.

* eldoc-box.el (eldoc-box--enable): Change :before-until to :before-while.
(eldoc-box--eldoc-message-function): Return nil if the message is not
multi-line, so that the default eldoc message function picks up the
message.
---
 eldoc-box.el | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/eldoc-box.el b/eldoc-box.el
index 984afd2..d83f8f1 100644
--- a/eldoc-box.el
+++ b/eldoc-box.el
@@ -145,7 +145,7 @@ See `eldoc-box-inhibit-display-when-moving'.")
 (defun eldoc-box--enable ()
   "Enable eldoc-box hover.
 Intended for internal use."
-  (add-function :before-until (local 'eldoc-message-function)
+  (add-function :before-while (local 'eldoc-message-function)
                 #'eldoc-box--eldoc-message-function)
   (when eldoc-box-clear-with-C-g
     (advice-add #'keyboard-quit :before #'eldoc-box-quit-frame)))
@@ -405,8 +405,10 @@ Checkout `lsp-ui-doc--make-frame', `lsp-ui-doc--move-frame'."
 (defun eldoc-box--eldoc-message-function (str &rest args)
   "Front-end for eldoc. Display STR in childframe and ARGS works like `message'."
   (when (and (stringp str) (not (equal str "")))
-    (let ((doc (apply #'format str args)))
-      (unless (and eldoc-box-only-multi-line (eq (cl-count ?\n doc) 0))
+    (let* ((doc (apply #'format str args))
+	   (multi-line-p (and eldoc-box-only-multi-line
+			      (eq (cl-count ?\n doc) 0))))
+      (unless multi-line-p
         (eldoc-box--display doc)
         (setq eldoc-box--last-point (point))
         ;; Why a timer? ElDoc is mainly used in minibuffer,
@@ -417,8 +419,8 @@ Checkout `lsp-ui-doc--make-frame', `lsp-ui-doc--move-frame'."
         ;; in `pre-command-hook', which means the timer is reset before every
         ;; command if `eldoc-box-hover-mode' is on and `eldoc-last-message' is not nil.
         (setq eldoc-box--cleanup-timer
-              (run-with-timer eldoc-box-cleanup-interval nil #'eldoc-box--maybe-cleanup))))
-    t))
+              (run-with-timer eldoc-box-cleanup-interval nil #'eldoc-box--maybe-cleanup)))
+      multi-line-p)))
 
 ;;;; Eglot helper