update-ref --stdin: make error messages more consistent

diff --git a/date.c b/date.c
index 83b4166344b31ea615603acaeb95a873f2c05077..e1a2cee5688a64555d7820e8e02e3e86839c9641 100644 (file)
--- a/date.c
+++ b/date.c
@@ -184,8 +184,10 @@ const char *show_date(unsigned long time, int tz, enum date_mode mode)
                tz = local_tzoffset(time);
 
        tm = time_to_tm(time, tz);
-       if (!tm)
-               return NULL;
+       if (!tm) {
+               tm = time_to_tm(0, 0);
+               tz = 0;
+       }
 
        strbuf_reset(&timebuf);
        if (mode == DATE_SHORT)
@@ -1113,3 +1115,20 @@ unsigned long approxidate_careful(const char *date, int *error_ret)
        gettimeofday(&tv, NULL);
        return approxidate_str(date, &tv, error_ret);
 }
+
+int date_overflows(unsigned long t)
+{
+       time_t sys;
+
+       /* If we overflowed our unsigned long, that's bad... */
+       if (t == ULONG_MAX)
+               return 1;
+
+       /*
+        * ...but we also are going to feed the result to system
+        * functions that expect time_t, which is often "signed long".
+        * Make sure that we fit into time_t, as well.
+        */
+       sys = t;
+       return t != sys || (t < 1) != (sys < 1);
+}