diff: fix bug where -D does not work

Problem reported by Robert Webb (bug#61193).
* NEWS: Mention this.
* src/diff.c (main): Omit stray ‘sizeof’.
* tests/ifdef: New test.
* tests/Makefile.am (TESTS): Add it.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/diff.c b/src/diff.c
index dd6f63b..2b4834f 100644
--- 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)