git: c550d07d8d5f - stable/13 - m4: Fix eval output width

The branch stable/13 has been updated by des:

URL: https://cgit.FreeBSD.org/src/commit/?id=c550d07d8d5f152b4b89f6c737188c30af199e3a

commit c550d07d8d5f152b4b89f6c737188c30af199e3a
Author:     Dag-Erling Smørgrav <des@FreeBSD.org>
AuthorDate: 2026-02-17 14:01:34 +0000
Commit:     Dag-Erling Smørgrav <des@FreeBSD.org>
CommitDate: 2026-02-26 04:03:51 +0000

    m4: Fix eval output width
    
    According to POSIX, the optional third argument is the minimum number
    of digits to print regardless of sign.  We interpreted it as the minimum
    width of the output including the sign.  Additionally, the variable used
    to hold this value was confusingly named “maxdigits”.
    
    PR:             293214
    MFC after:      1 week
    Sponsored by:   Klara, Inc.
    Reviewed by:    imp
    Differential Revision:  https://reviews.freebsd.org/D55311
    
    (cherry picked from commit 507c611aeac7ca9aed12353b1044bb21ab00afae)
---
 usr.bin/m4/eval.c                 | 8 ++++----
 usr.bin/m4/misc.c                 | 2 --
 usr.bin/m4/tests/eval.m4          | 2 ++
 usr.bin/m4/tests/regress.eval.out | 2 ++
 4 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/usr.bin/m4/eval.c b/usr.bin/m4/eval.c
index 82218eb9ba1c..dba903c2ba24 100644
--- a/usr.bin/m4/eval.c
+++ b/usr.bin/m4/eval.c
@@ -178,7 +178,7 @@ expand_builtin(const char *argv[], int argc, int td)
 	 */
 	{
 		int base = 10;
-		int maxdigits = 0;
+		int mindigits = 0;
 		const char *errstr;
 
 		if (argc > 3) {
@@ -189,14 +189,14 @@ expand_builtin(const char *argv[], int argc, int td)
 			}
 		}
 		if (argc > 4) {
-			maxdigits = strtonum(argv[4], 0, INT_MAX, &errstr);
+			mindigits = strtonum(argv[4], 0, INT_MAX, &errstr);
 			if (errstr) {
-				m4errx(1, "expr: maxdigits is %s: %s.",
+				m4errx(1, "expr: mindigits is %s: %s.",
 				    errstr, argv[4]);
 			}
 		}
 		if (argc > 2)
-			pbnumbase(expr(argv[2]), base, maxdigits);
+			pbnumbase(expr(argv[2]), base, mindigits);
 		break;
 	}
 
diff --git a/usr.bin/m4/misc.c b/usr.bin/m4/misc.c
index 7d2473f88168..a6abce4936b4 100644
--- a/usr.bin/m4/misc.c
+++ b/usr.bin/m4/misc.c
@@ -139,8 +139,6 @@ pbnumbase(int n, int base, int d)
 	}
 	while ((num /= base) > 0);
 
-	if (n < 0)
-		printed++;
 	while (printed++ < d)
 		pushback('0');
 
diff --git a/usr.bin/m4/tests/eval.m4 b/usr.bin/m4/tests/eval.m4
index 1d3f886d0d89..dc0fada781f1 100644
--- a/usr.bin/m4/tests/eval.m4
+++ b/usr.bin/m4/tests/eval.m4
@@ -3,3 +3,5 @@ dnl expr parser
 eval(224&127)
 eval(224|127)
 eval(224&&127)
+eval(3-2, 10, 5)
+eval(2-3, 10, 4)
diff --git a/usr.bin/m4/tests/regress.eval.out b/usr.bin/m4/tests/regress.eval.out
index 7298b3f43840..b1bb211dcb64 100644
--- a/usr.bin/m4/tests/regress.eval.out
+++ b/usr.bin/m4/tests/regress.eval.out
@@ -1,3 +1,5 @@
 96
 255
 1
+00001
+-0001