commit 2293aea1252c99834c4117f51b8e4f3f625ab2ca
from: Kirill A. Korinsky <kirill@korins.ky>
date: Mon Jun  2 19:57:23 2025 UTC

prevent dkim_ar_cat from lose last character

It losed the last character when the length resulted string was multiple
of 256

commit - 36daa2d4bbadd128a286caf4ecdf800c45c65aa3
commit + 2293aea1252c99834c4117f51b8e4f3f625ab2ca
blob - 9b1b427984b0c93f53dfc1b7c504a78863566cdd
blob + 16d759acc94b7412e13b496e71fa3e8e82e14a3c
--- main.c
+++ main.c
@@ -1738,7 +1738,7 @@ dkim_ar_cat(char **ar, size_t *n, size_t aroff, const 
 	va_start(ap, fmt);
 	size = vsnprintf(*ar + aroff, *n - aroff, fmt, ap);
 	va_end(ap);
-	if (size + aroff <= *n)
+	if (size + aroff < *n)
 		return (ssize_t)size + aroff;
 	nn = (((aroff + size)  / 256) + 1) * 256;
 	artmp = realloc(*ar, nn);