Do not format USEC_INFINITY as NULL

systemctl would print 'CPUQuotaPerSecUSec=(null)' for no limit. This
does not look right.

Since USEC_INFINITY is one of the valid values, format_timespan()
could return NULL, and we should wrap every use of it in strna() or
similar. But most callers didn't do that, and it seems more robust to
return a string ("infinity") that makes sense most of the time, even
if in some places the result will not be grammatically correct.

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>

1 files changed, 2 insertions, 5 deletions

diff --git a/src/shared/time-util.c b/src/shared/time-util.c
index 3df35b8e24..4e12ea3ca6 100644
--- a/src/shared/time-util.c
+++ b/src/shared/time-util.c
@@ -99,11 +99,8 @@ char *format_timespan(char *buf, size_t l, usec_t t, usec_t accuracy) {
         assert(buf);
         assert(l > 0);
 
-        if (t == USEC_INFINITY)
-                return NULL;
-
-        if (t <= 0) {
-                snprintf(p, l, "0");
+        if (t == USEC_INFINITY || t <= 0) {
+                strncpy(p, t == USEC_INFINITY ? "infinity" : "0", l);
                 p[l-1] = 0;
                 return p;
         }