Make a flymake.texi code example more resilient

* doc/misc/flymake.texi (An annotated example backend): Make the
example code resilient wrt. narrowed buffers (bug#51437).

diff --git a/doc/misc/flymake.texi b/doc/misc/flymake.texi
index b4e7f3a41f882d732b98e97cda82bc2e614d0afb..7406557623f69696e4e3d1ed5fbfce14d8f6f65e 100644 (file)
--- a/doc/misc/flymake.texi
+++ b/doc/misc/flymake.texi
@@ -801,6 +801,7 @@ Binding,,, elisp, The Emacs Lisp Reference Manual}) to be active.
                        for type = (if (string-match "^warning" msg)
                                       :warning
                                     :error)
+                       when (and beg end)
                        collect (flymake-make-diagnostic source
                                                         beg
                                                         end