I noticed git diffstat only pluralises {dele,inser}tion(s) when more
than 1 change occurs. And, relatedly, when there aren't any
{dele,inser}tions, that substring is elided altogether.

For an example of the latter, see this diff[0] to tech@ where there were
no deletions and observe how that part of the summary is absent:

----8<--------
 regress/lib/libz/Makefile          | 15 +++++++++++++++
 regress/lib/libz/utils_unittest.cc |  3 +++
 2 files changed, 18 insertions(+)
-------->8----

For an example of the former, see this diff[1] to tech@ where the total
change was just 1 insertion and 1 deletion:

----8<--------
 ssh.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
-------->8----

I agree with the second example (i.e., don't use a plural noun after 1),
but I don't particularly like the idea of eliding a summary total
altogether, and prefer we continue displaying "0 {dele,inser}tions".
On that note, I think 0 should keep the plural form (e.g., 0 insertions,
not 0 insertion).

In short, the below diff changes the top into the bottom:

  1 file changed, 1 insertions(+), 1 deletions(-)
  1 file changed, 1 insertion(+), 1 deletion(-)

ok?

-----------------------------------------------
commit ba0c0161716ca82e858e5bf748fa7bf3cd33862e (main)
from: Mark Jamsek <mark@jamsek.dev>
date: Sun Jan 15 10:32:04 2023 UTC
 
 don't use plural noun after 1 in diffstat total
 
 Use singular form when appropriate; for example, turn the top into the bottom:
 
   1 file changed, 1 insertions(+), 1 deletions(-)
   1 file changed, 1 insertion(+), 1 deletion(-)
 
diff 760079985fc2d63ebd4155a76d4f0d20fbc2f4c5 ba0c0161716ca82e858e5bf748fa7bf3cd33862e
commit - 760079985fc2d63ebd4155a76d4f0d20fbc2f4c5
commit + ba0c0161716ca82e858e5bf748fa7bf3cd33862e
blob - a20fdf567d2fb43a228a54708fee12c13f94796b
blob + e432b18620ea668642106a045956a1a96bef04bc
--- got/got.c
+++ got/got.c
@@ -4168,8 +4168,9 @@ print_diffstat(struct got_diffstat_cb_arg *dsa, struct
 		printf(" %c  %s%*c | %*d+ %*d-\n", cp->status, pe->path, pad,
 		    ' ', dsa->add_cols + 1, cp->add, dsa->rm_cols + 1, cp->rm);
 	}
-	printf("\n%d file%s changed, %d insertions(+), %d deletions(-)\n\n",
-	    dsa->nfiles, dsa->nfiles > 1 ? "s" : "", dsa->ins, dsa->del);
+	printf("\n%d file%s changed, %d insertion%s(+), %d deletion%s(-)\n\n",
+	    dsa->nfiles, dsa->nfiles > 1 ? "s" : "", dsa->ins,
+	    dsa->ins != 1 ? "s" : "", dsa->del, dsa->del != 1 ? "s" : "");
 
 	if (fflush(stdout) != 0)
 		return got_error_from_errno("fflush");
blob - 3bf0246d75b75fc92ca14ca210759bab8aebcdc2
blob + 8766355007a2f2ff1724f384dc2bae3e21660b51
--- tog/tog.c
+++ tog/tog.c
@@ -4720,8 +4720,9 @@ write_commit_info(struct got_diff_line **lines, size_t
 		goto done;
 
 	n = fprintf(outfile,
-	    "%d file%s changed, %d insertions(+), %d deletions(-)\n",
-	    dsa.nfiles, dsa.nfiles > 1 ? "s" : "", dsa.ins, dsa.del);
+	    "%d file%s changed, %d insertion%s(+), %d deletion%s(-)\n",
+	    dsa.nfiles, dsa.nfiles > 1 ? "s" : "", dsa.ins,
+	    dsa.ins != 1 ? "s" : "", dsa.del, dsa.del != 1 ? "s" : "");
 	if (n < 0) {
 		err = got_error_from_errno("fprintf");
 		goto done;

[0]: https://marc.info/?l=openbsd-tech&m=166714432227960&w=2
[1]: https://marc.info/?l=openbsd-tech&m=166492712423323&w=2

-- 
Mark Jamsek <fnc.bsdbox.org>
GPG: F2FF 13DE 6A06 C471 CA80  E6E2 2930 DC66 86EE CF68