From 2ded5938753a2fac94e5aebce2e97fc5b4d91076 Mon Sep 17 00:00:00 2001
From: Lars Ingebrigtsen <larsi@gnus.org>
Date: Thu, 3 Feb 2022 20:33:58 +0100
Subject: [PATCH] Make sort-numeric-fields resilient towards blank lines

* lisp/sort.el (sort-numeric-fields): Don't signal an error on
blank lines (bug#31800).
---
 lisp/sort.el | 43 ++++++++++++++++++++++++-------------------
 1 file changed, 24 insertions(+), 19 deletions(-)

diff --git a/lisp/sort.el b/lisp/sort.el
index eb8e2787d1e..90eee01caf4 100644
--- a/lisp/sort.el
+++ b/lisp/sort.el
@@ -286,25 +286,30 @@ FIELD, BEG and END.  BEG and END specify region to sort."
   (interactive "p\nr")
   (let ;; To make `end-of-line' and etc. to ignore fields.
       ((inhibit-field-text-motion t))
-    (sort-fields-1 field beg end
-		   (lambda ()
-		     (sort-skip-fields field)
-		     (let* ((case-fold-search t)
-			    (base
-			     (if (looking-at "\\(0x\\)[0-9a-f]\\|\\(0\\)[0-7]")
-				 (cond ((match-beginning 1)
-					(goto-char (match-end 1))
-					16)
-				       ((match-beginning 2)
-					(goto-char (match-end 2))
-					8)
-				       (t nil)))))
-		       (string-to-number (buffer-substring (point)
-							   (save-excursion
-							     (forward-sexp 1)
-							     (point)))
-					 (or base sort-numeric-base))))
-		   nil)))
+    (sort-fields-1
+     field beg end
+     (lambda ()
+       ;; Don't try to parse blank lines (they'll be
+       ;; sorted at the start).
+       (if (looking-at "[\t ]*$")
+           0
+	 (sort-skip-fields field)
+	 (let* ((case-fold-search t)
+		(base
+		 (if (looking-at "\\(0x\\)[0-9a-f]\\|\\(0\\)[0-7]")
+		     (cond ((match-beginning 1)
+			    (goto-char (match-end 1))
+			    16)
+			   ((match-beginning 2)
+			    (goto-char (match-end 2))
+			    8)
+			   (t nil)))))
+	   (string-to-number (buffer-substring (point)
+					       (save-excursion
+						 (forward-sexp 1)
+						 (point)))
+			     (or base sort-numeric-base)))))
+     nil)))
 
 ;;;;;###autoload
 ;;(defun sort-float-fields (field beg end)
-- 
2.39.5