https://debbugs.gnu.org/cgi/bugreport.cgi?bug=61193
https://git.savannah.gnu.org/cgit/groff.git/commit/?id=10274fb69e517b2c4b10fcd0ba3347e5bd0eefd7
https://git.savannah.gnu.org/cgit/diffutils.git/commit/?id=ba08fbbb0ca5da455bf695236c57bc50e7faed50

From ba08fbbb0ca5da455bf695236c57bc50e7faed50 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Fri, 10 Feb 2023 15:33:40 -0800
Subject: diff: fix bug where -D does not work
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Problem reported by Robert Webb (bug#61193).
* src/diff.c (main): Omit stray ‘sizeof’.
* tests/ifdef: New test.
* tests/Makefile.am (TESTS): Add it.
--- a/src/diff.c
+++ b/src/diff.c
@@ -416,7 +416,7 @@ main (int argc, char **argv)
 	    char *base = b;
 	    int changes = 0;
 
-	    for (i = 0; i < sizeof sizeof C_ifdef_group_formats; i++)
+	    for (i = 0; i < sizeof C_ifdef_group_formats; i++)
 	      {
 		char ch = C_ifdef_group_formats[i];
 		switch (ch)