Don't hide flymake diagnostics on empty first line (bug#70310)

A diagnostic first in the buffer, typically the lexical cookie warning,
got lost if that line was empty.

* lisp/progmodes/elisp-mode.el (elisp-flymake--byte-compile-done):
Make sure the location interval doesn't go beyond the buffer bounds.

1 files changed, 7 insertions, 2 deletions

diff --git a/lisp/progmodes/elisp-mode.el b/lisp/progmodes/elisp-mode.el
index 9b4c3f994cd..3383841391d 100644
--- a/lisp/progmodes/elisp-mode.el
+++ b/lisp/progmodes/elisp-mode.el
@@ -2151,8 +2151,13 @@ Calls REPORT-FN directly."
                                  (point-max)))
                   collect (flymake-make-diagnostic
                            (current-buffer)
-                           (if (= beg end) (1- beg) beg)
-                           end
+                           (if (= beg end)
+                               (max (1- beg) (point-min))
+                             beg)
+                           (if (= beg end)
+                               (min (max beg (1+ (point-min)))
+                                    (point-max))
+                             end)
                            level
                            string)))))))