util: fix sign-compare warning

diff --git a/src/basic/time-util.c b/src/basic/time-util.c
index 8ccb4a9..434159f 100644 (file)
--- a/src/basic/time-util.c
+++ b/src/basic/time-util.c
@@ -267,13 +267,12 @@ static char *format_timestamp_internal(
 
         assert(buf);
 
-        if (l <
-            3 +                  /* week day */
-            1 + 10 +             /* space and date */
-            1 + 8 +              /* space and time */
-            (us ? 1 + 6 : 0) +   /* "." and microsecond part */
-            1 + 1 +              /* space and shortest possible zone */
-            1)
+        if (l < (size_t) (3 +                  /* week day */
+                          1 + 10 +             /* space and date */
+                          1 + 8 +              /* space and time */
+                          (us ? 1 + 6 : 0) +   /* "." and microsecond part */
+                          1 + 1 +              /* space and shortest possible zone */
+                          1))
                 return NULL; /* Not enough space even for the shortest form. */
         if (t <= 0 || t == USEC_INFINITY)
                 return NULL; /* Timestamp is unset */