[tz] [PROPOSED 2/2] Add comment re TZLOAD_FROMENV omission

[Paul Eggert via tz]

* localtime.c (localtime): Add comment re difference from FreeBSD 15.1.
---
 localtime.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/localtime.c b/localtime.c
index 7c06e370..29a70eb4 100644
--- a/localtime.c
+++ b/localtime.c
@@ -938,6 +938,9 @@ tzloadbody(char const *name, struct state *sp, char 
tzloadflags,
                name = TZDEFAULT;
                if (! name)
                  return EINVAL;
+               /* Omit "tzloadflags &= ~TZLOAD_FROMENV;" here, as that
+                  would hurt performance by rereading and reanalyzing the
+                  TZDEFAULT file even when it is unchanged.  */
        }
 
        if (name[0] == ':')
-- 
2.53.0