revision.c: explain what tree_difference does

diff --git a/date.c b/date.c
index e387dcd3976d8e12afdce5d7600ca0022f4ca835..0ceccbe03401faa67836577b9bdbe139fe025dd5 100644 (file)
--- a/date.c
+++ b/date.c
@@ -4,9 +4,6 @@
  * Copyright (C) Linus Torvalds, 2005
  */
 
-#include <time.h>
-#include <sys/time.h>
-
 #include "cache.h"
 
 static time_t my_mktime(struct tm *tm)
@@ -58,19 +55,18 @@ static struct tm *time_to_tm(unsigned long time, int tz)
        return gmtime(&t);
 }
 
-const char *show_date(unsigned long time, int tz, int relative)
+const char *show_date(unsigned long time, int tz, enum date_mode mode)
 {
        struct tm *tm;
        static char timebuf[200];
 
-       if (relative) {
+       if (mode == DATE_RELATIVE) {
                unsigned long diff;
-               time_t t = gm_time_t(time, tz);
                struct timeval now;
                gettimeofday(&now, NULL);
-               if (now.tv_sec < t)
+               if (now.tv_sec < time)
                        return "in the future";
-               diff = now.tv_sec - t;
+               diff = now.tv_sec - time;
                if (diff < 90) {
                        snprintf(timebuf, sizeof(timebuf), "%lu seconds ago", diff);
                        return timebuf;
@@ -109,12 +105,16 @@ const char *show_date(unsigned long time, int tz, int relative)
        tm = time_to_tm(time, tz);
        if (!tm)
                return NULL;
-       sprintf(timebuf, "%.3s %.3s %d %02d:%02d:%02d %d %+05d",
-               weekday_names[tm->tm_wday],
-               month_names[tm->tm_mon],
-               tm->tm_mday,
-               tm->tm_hour, tm->tm_min, tm->tm_sec,
-               tm->tm_year + 1900, tz);
+       if (mode == DATE_SHORT)
+               sprintf(timebuf, "%04d-%02d-%02d", tm->tm_year + 1900,
+                               tm->tm_mon + 1, tm->tm_mday);
+       else
+               sprintf(timebuf, "%.3s %.3s %d %02d:%02d:%02d %d %+05d",
+                               weekday_names[tm->tm_wday],
+                               month_names[tm->tm_mon],
+                               tm->tm_mday,
+                               tm->tm_hour, tm->tm_min, tm->tm_sec,
+                               tm->tm_year + 1900, tz);
        return timebuf;
 }
 
@@ -256,8 +256,12 @@ static int match_alpha(const char *date, struct tm *tm, int *offset)
        }
 
        if (match_string(date, "PM") == 2) {
-               if (tm->tm_hour > 0 && tm->tm_hour < 12)
-                       tm->tm_hour += 12;
+               tm->tm_hour = (tm->tm_hour % 12) + 12;
+               return 2;
+       }
+
+       if (match_string(date, "AM") == 2) {
+               tm->tm_hour = (tm->tm_hour % 12) + 0;
                return 2;
        }
 
@@ -598,6 +602,34 @@ static void date_tea(struct tm *tm, int *num)
        date_time(tm, 17);
 }
 
+static void date_pm(struct tm *tm, int *num)
+{
+       int hour, n = *num;
+       *num = 0;
+
+       hour = tm->tm_hour;
+       if (n) {
+               hour = n;
+               tm->tm_min = 0;
+               tm->tm_sec = 0;
+       }
+       tm->tm_hour = (hour % 12) + 12;
+}
+
+static void date_am(struct tm *tm, int *num)
+{
+       int hour, n = *num;
+       *num = 0;
+
+       hour = tm->tm_hour;
+       if (n) {
+               hour = n;
+               tm->tm_min = 0;
+               tm->tm_sec = 0;
+       }
+       tm->tm_hour = (hour % 12);
+}
+
 static const struct special {
        const char *name;
        void (*fn)(struct tm *, int *);
@@ -606,6 +638,8 @@ static const struct special {
        { "noon", date_noon },
        { "midnight", date_midnight },
        { "tea", date_tea },
+       { "PM", date_pm },
+       { "AM", date_am },
        { NULL }
 };
 
@@ -712,6 +746,27 @@ static const char *approxidate_alpha(const char *date, struct tm *tm, int *num)
        return end;
 }
 
+static const char *approxidate_digit(const char *date, struct tm *tm, int *num)
+{
+       char *end;
+       unsigned long number = strtoul(date, &end, 10);
+
+       switch (*end) {
+       case ':':
+       case '.':
+       case '/':
+       case '-':
+               if (isdigit(end[1])) {
+                       int match = match_multi_number(number, *end, date, end, tm);
+                       if (match)
+                               return date + match;
+               }
+       }
+
+       *num = number;
+       return end;
+}
+
 unsigned long approxidate(const char *date)
 {
        int number = 0;
@@ -731,9 +786,7 @@ unsigned long approxidate(const char *date)
                        break;
                date++;
                if (isdigit(c)) {
-                       char *end;
-                       number = strtoul(date-1, &end, 10);
-                       date = end;
+                       date = approxidate_digit(date-1, &tm, &number);
                        continue;
                }
                if (isalpha(c))