Eglot: really fix bug#79259

The previous change actually introduced a bug in a closely
related but distinct place.  We need to address the off-by-one
in the 'substring' call, not the 'add-face-text-property'.

* lisp/progmodes/eglot.el (eglot--sig-info): Fixup.

1 files changed, 2 insertions, 2 deletions

diff --git a/lisp/progmodes/eglot.el b/lisp/progmodes/eglot.el
index 475b5e13f1b..d06b97b431e 100644
--- a/lisp/progmodes/eglot.el
+++ b/lisp/progmodes/eglot.el
@@ -3718,7 +3718,7 @@ for which LSP on-type-formatting should be requested."
                        (let ((case-fold-search nil))
                          (and (search-forward parlabel (line-end-position) t)
                               (list (match-beginning 0) (match-end 0))))
-                     (list (aref parlabel 0) (aref parlabel 1)))))
+                     (list (1+ (aref parlabel 0)) (1+ (aref parlabel 1))))))
                (if (and beg end)
                    (add-face-text-property
                     beg end
@@ -3731,7 +3731,7 @@ for which LSP on-type-formatting should be requested."
              (insert "\n  "
                      (propertize
                       (if (stringp parlabel) parlabel
-                        (apply #'substring siglabel (mapcar #'1+ parlabel)))
+                        (substring siglabel (aref parlabel 0) (aref parlabel 1)))
                       'face (and (eq i active-param) 'eldoc-highlight-function-argument))
                      ": " fpardoc)))))
       (buffer-string))))