Adjust not-too-sane calculation of DDD value for to_char(interval).

Per gripe from Chris Matheson.

diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index 90e940e7b9c693d655bd4b0e6a41d9f32557c5eb..de84afe42c9899fef29c8e9803a8e548be42693d 100644 (file)
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -1,7 +1,7 @@
 /* -----------------------------------------------------------------------
  * formatting.c
  *
- * $PostgreSQL: pgsql/src/backend/utils/adt/formatting.c,v 1.100 2005/10/15 02:49:28 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/formatting.c,v 1.101 2005/10/20 15:59:46 tgl Exp $
  *
  *
  *      Portions Copyright (c) 1999-2005, PostgreSQL Global Development Group
@@ -2724,15 +2724,12 @@ static text *
 datetime_to_char_body(TmToChar *tmtc, text *fmt, bool is_interval)
 {
        FormatNode *format;
-       struct pg_tm *tm = NULL;
        char       *fmt_str,
                           *result;
        bool            incache;
        int                     fmt_len = VARSIZE(fmt) - VARHDRSZ;
-
-       tm = tmtcTm(tmtc);
-       tm->tm_wday = (date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) + 1) % 7;
-       tm->tm_yday = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) - date2j(tm->tm_year, 1, 1) + 1;
+       int                     reslen;
+       text       *res;
 
        /*
         * Convert fmt to C string
@@ -2742,9 +2739,10 @@ datetime_to_char_body(TmToChar *tmtc, text *fmt, bool is_interval)
        *(fmt_str + fmt_len) = '\0';
 
        /*
-        * Allocate result
+        * Allocate workspace for result as C string
         */
        result = palloc((fmt_len * DCH_MAX_ITEM_SIZ) + 1);
+       *result = '\0';
 
        /*
         * Allocate new memory if format picture is bigger than static cache and
@@ -2790,6 +2788,7 @@ datetime_to_char_body(TmToChar *tmtc, text *fmt, bool is_interval)
                format = ent->format;
        }
 
+       /* The real work is here */
        DCH_processor(format, result, true, is_interval, (void *) tmtc);
 
        if (!incache)
@@ -2797,26 +2796,14 @@ datetime_to_char_body(TmToChar *tmtc, text *fmt, bool is_interval)
 
        pfree(fmt_str);
 
-       /*
-        * for result is allocated max memory, which current format-picture needs,
-        * now it allocate result with real size
-        */
-       if (result && *result)
-       {
-               int                     len = strlen(result);
-
-               if (len)
-               {
-                       text       *res = (text *) palloc(len + 1 + VARHDRSZ);
+       /* convert C-string result to TEXT format */
+       reslen = strlen(result);
+       res = (text *) palloc(reslen + VARHDRSZ);
+       memcpy(VARDATA(res), result, reslen);
+       VARATT_SIZEP(res) = reslen + VARHDRSZ;
 
-                       memcpy(VARDATA(res), result, len);
-                       VARATT_SIZEP(res) = len + VARHDRSZ;
-                       pfree(result);
-                       return res;
-               }
-       }
        pfree(result);
-       return NULL;
+       return res;
 }
 
 /****************************************************************************
@@ -2834,17 +2821,24 @@ timestamp_to_char(PG_FUNCTION_ARGS)
        text       *fmt = PG_GETARG_TEXT_P(1),
                           *res;
        TmToChar        tmtc;
+       struct pg_tm *tm;
+       int                     thisdate;
 
        if ((VARSIZE(fmt) - VARHDRSZ) <= 0 || TIMESTAMP_NOT_FINITE(dt))
                PG_RETURN_NULL();
 
        ZERO_tmtc(&tmtc);
+       tm = tmtcTm(&tmtc);
 
-       if (timestamp2tm(dt, NULL, tmtcTm(&tmtc), &tmtcFsec(&tmtc), NULL, NULL) != 0)
+       if (timestamp2tm(dt, NULL, tm, &tmtcFsec(&tmtc), NULL, NULL) != 0)
                ereport(ERROR,
                                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                                 errmsg("timestamp out of range")));
 
+       thisdate = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday);
+       tm->tm_wday = (thisdate + 1) % 7;
+       tm->tm_yday = thisdate - date2j(tm->tm_year, 1, 1) + 1;
+
        if (!(res = datetime_to_char_body(&tmtc, fmt, false)))
                PG_RETURN_NULL();
 
@@ -2859,17 +2853,24 @@ timestamptz_to_char(PG_FUNCTION_ARGS)
                           *res;
        TmToChar        tmtc;
        int                     tz;
+       struct pg_tm *tm;
+       int                     thisdate;
 
        if ((VARSIZE(fmt) - VARHDRSZ) <= 0 || TIMESTAMP_NOT_FINITE(dt))
                PG_RETURN_NULL();
 
        ZERO_tmtc(&tmtc);
+       tm = tmtcTm(&tmtc);
 
-       if (timestamp2tm(dt, &tz, tmtcTm(&tmtc), &tmtcFsec(&tmtc), &tmtcTzn(&tmtc), NULL) != 0)
+       if (timestamp2tm(dt, &tz, tm, &tmtcFsec(&tmtc), &tmtcTzn(&tmtc), NULL) != 0)
                ereport(ERROR,
                                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                                 errmsg("timestamp out of range")));
 
+       thisdate = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday);
+       tm->tm_wday = (thisdate + 1) % 7;
+       tm->tm_yday = thisdate - date2j(tm->tm_year, 1, 1) + 1;
+
        if (!(res = datetime_to_char_body(&tmtc, fmt, false)))
                PG_RETURN_NULL();
 
@@ -2888,15 +2889,20 @@ interval_to_char(PG_FUNCTION_ARGS)
        text       *fmt = PG_GETARG_TEXT_P(1),
                           *res;
        TmToChar        tmtc;
+       struct pg_tm *tm;
 
        if ((VARSIZE(fmt) - VARHDRSZ) <= 0)
                PG_RETURN_NULL();
 
        ZERO_tmtc(&tmtc);
+       tm = tmtcTm(&tmtc);
 
-       if (interval2tm(*it, tmtcTm(&tmtc), &tmtcFsec(&tmtc)) != 0)
+       if (interval2tm(*it, tm, &tmtcFsec(&tmtc)) != 0)
                PG_RETURN_NULL();
 
+       /* wday is meaningless, yday approximates the total span in days */
+       tm->tm_yday = (tm->tm_year * MONTHS_PER_YEAR + tm->tm_mon) * DAYS_PER_MONTH + tm->tm_mday;
+
        if (!(res = datetime_to_char_body(&tmtc, fmt, true)))
                PG_RETURN_NULL();