Fix args-out-of-range error in format.el

* lisp/format.el (format-deannotate-region): Ignore todo items
with FROM > TO.  (Bug#47277)

1 files changed, 11 insertions, 7 deletions

diff --git a/lisp/format.el b/lisp/format.el
index 4209fc6401a..3e2d92fef13 100644
--- a/lisp/format.el
+++ b/lisp/format.el
@@ -747,13 +747,17 @@ to write these unknown annotations back into the file."
 
             (if (numberp val)   ; add to ambient value if numeric
                 (format-property-increment-region from to prop val 0)
-              (put-text-property
-               from to prop
-               (cond ((get prop 'format-list-valued) ; value gets consed onto
-                                                     ; list-valued properties
-                      (let ((prev (get-text-property from prop)))
-                        (cons val (if (listp prev) prev (list prev)))))
-                     (t val))))) ; normally, just set to val.
+              ;; Kludge alert: ignore items with reversed order of
+              ;; FROM and TO.  They seem to be redundant anyway, and
+              ;; in one case I've seen them refer to EOB.
+              (when (<= from to)
+                (put-text-property
+                 from to prop
+                 (cond ((get prop 'format-list-valued) ; value gets consed onto
+                                                       ; list-valued properties
+                        (let ((prev (get-text-property from prop)))
+                          (cons val (if (listp prev) prev (list prev)))))
+                       (t val)))))) ; normally, just set to val.
           (setq todo (cdr todo)))
 
         (if unknown-ans