grep doc: add --break / --heading / -W to synopsis

[git.git] / date.c

diff --git a/date.c b/date.c
index 353e0a5e53f13c36549e65452931f254de3423c4..a5055ca09dc1fafce2b9434c4fda02ad4f8e117f 100644 (file)
--- a/date.c
+++ b/date.c
@@ -597,6 +597,33 @@ static int date_string(unsigned long date, int offset, char *buf, int len)
        return snprintf(buf, len, "%lu %c%02d%02d", date, sign, offset / 60, offset % 60);
 }
 
+/*
+ * Parse a string like "0 +0000" as ancient timestamp near epoch, but
+ * only when it appears not as part of any other string.
+ */
+static int match_object_header_date(const char *date, unsigned long *timestamp, int *offset)
+{
+       char *end;
+       unsigned long stamp;
+       int ofs;
+
+       if (*date < '0' || '9' <= *date)
+               return -1;
+       stamp = strtoul(date, &end, 10);
+       if (*end != ' ' || stamp == ULONG_MAX || (end[1] != '+' && end[1] != '-'))
+               return -1;
+       date = end + 2;
+       ofs = strtol(date, &end, 10);
+       if ((*end != '\0' && (*end != '\n')) || end != date + 4)
+               return -1;
+       ofs = (ofs / 100) * 60 + (ofs % 100);
+       if (date[-1] == '-')
+               ofs = -ofs;
+       *timestamp = stamp;
+       *offset = ofs;
+       return 0;
+}
+
 /* Gr. strptime is crap for this; it doesn't have a way to require RFC2822
    (i.e. English) day/month names, and it doesn't work correctly with %z. */
 int parse_date_basic(const char *date, unsigned long *timestamp, int *offset)
@@ -622,6 +649,9 @@ int parse_date_basic(const char *date, unsigned long *timestamp, int *offset)
        *offset = -1;
        tm_gmt = 0;
 
+       if (*date == '@' &&
+           !match_object_header_date(date + 1, timestamp, offset))
+               return 0; /* success */
        for (;;) {
                int match = 0;
                unsigned char c = *date;