Clean up the code for to_timestamp's conversion of year plus ISO day number

to date, as per bug #4702 and subsequent discussion.  In particular, make it
work for years specified using AD/BC or CC fields, and fix the test for "no
year specified" so that it doesn't trigger inappropriately for 1 BC (which it
was doing even in code paths that had nothing to do with to_timestamp).  I
also did some minor code beautification in the non-ISO-day-number code path.

This area has been busted all along, but because the code has been rewritten
repeatedly, it would be considerable trouble to back-patch.  It's such a
corner case that it doesn't seem worth the effort.

diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index 81bda817e815f594e322cf5a7503a4b219616441..3498e2c503f8eef4eab715378ed56289b5105bd9 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 1.155 2009/03/12 00:53:25 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/formatting.c,v 1.156 2009/03/15 20:31:19 tgl Exp $
  *
  *
  *  Portions Copyright (c) 1999-2009, PostgreSQL Global Development Group
@@ -709,13 +709,13 @@ typedef enum
  */
 static const KeyWord DCH_keywords[] = {
 /* name, len, id, is_digit, date_mode */
-   {"A.D.", 4, DCH_A_D, FALSE, FROM_CHAR_DATE_GREGORIAN},  /* A */
+   {"A.D.", 4, DCH_A_D, FALSE, FROM_CHAR_DATE_NONE},       /* A */
    {"A.M.", 4, DCH_A_M, FALSE, FROM_CHAR_DATE_NONE},
-   {"AD", 2, DCH_AD, FALSE, FROM_CHAR_DATE_GREGORIAN},
+   {"AD", 2, DCH_AD, FALSE, FROM_CHAR_DATE_NONE},
    {"AM", 2, DCH_AM, FALSE, FROM_CHAR_DATE_NONE},
-   {"B.C.", 4, DCH_B_C, FALSE, FROM_CHAR_DATE_GREGORIAN},  /* B */
-   {"BC", 2, DCH_BC, FALSE, FROM_CHAR_DATE_GREGORIAN},
-   {"CC", 2, DCH_CC, TRUE, FROM_CHAR_DATE_GREGORIAN},      /* C */
+   {"B.C.", 4, DCH_B_C, FALSE, FROM_CHAR_DATE_NONE},       /* B */
+   {"BC", 2, DCH_BC, FALSE, FROM_CHAR_DATE_NONE},
+   {"CC", 2, DCH_CC, TRUE, FROM_CHAR_DATE_NONE},           /* C */
    {"DAY", 3, DCH_DAY, FALSE, FROM_CHAR_DATE_NONE},        /* D */
    {"DDD", 3, DCH_DDD, TRUE, FROM_CHAR_DATE_GREGORIAN},
    {"DD", 2, DCH_DD, TRUE, FROM_CHAR_DATE_GREGORIAN},
@@ -757,13 +757,13 @@ static const KeyWord DCH_keywords[] = {
    {"YYY", 3, DCH_YYY, TRUE, FROM_CHAR_DATE_GREGORIAN},
    {"YY", 2, DCH_YY, TRUE, FROM_CHAR_DATE_GREGORIAN},
    {"Y", 1, DCH_Y, TRUE, FROM_CHAR_DATE_GREGORIAN},
-   {"a.d.", 4, DCH_a_d, FALSE, FROM_CHAR_DATE_GREGORIAN},  /* a */
+   {"a.d.", 4, DCH_a_d, FALSE, FROM_CHAR_DATE_NONE},       /* a */
    {"a.m.", 4, DCH_a_m, FALSE, FROM_CHAR_DATE_NONE},
-   {"ad", 2, DCH_ad, FALSE, FROM_CHAR_DATE_GREGORIAN},
+   {"ad", 2, DCH_ad, FALSE, FROM_CHAR_DATE_NONE},
    {"am", 2, DCH_am, FALSE, FROM_CHAR_DATE_NONE},
-   {"b.c.", 4, DCH_b_c, FALSE, FROM_CHAR_DATE_GREGORIAN},  /* b */
-   {"bc", 2, DCH_bc, FALSE, FROM_CHAR_DATE_GREGORIAN},
-   {"cc", 2, DCH_CC, TRUE, FROM_CHAR_DATE_GREGORIAN},      /* c */
+   {"b.c.", 4, DCH_b_c, FALSE, FROM_CHAR_DATE_NONE},       /* b */
+   {"bc", 2, DCH_bc, FALSE, FROM_CHAR_DATE_NONE},
+   {"cc", 2, DCH_CC, TRUE, FROM_CHAR_DATE_NONE},           /* c */
    {"day", 3, DCH_day, FALSE, FROM_CHAR_DATE_NONE},        /* d */
    {"ddd", 3, DCH_DDD, TRUE, FROM_CHAR_DATE_GREGORIAN},
    {"dd", 2, DCH_DD, TRUE, FROM_CHAR_DATE_GREGORIAN},
@@ -3281,41 +3281,41 @@ do_to_timestamp(text *date_txt, text *fmt,
         * be interpreted as a Gregorian day-of-year, or an ISO week date
         * day-of-year.
         */
+
+       if (!tm->tm_year && !tmfc.bc)
+           ereport(ERROR,
+                   (errcode(ERRCODE_INVALID_DATETIME_FORMAT),
+                    errmsg("cannot calculate day of year without year information")));
+
        if (tmfc.mode == FROM_CHAR_DATE_ISOWEEK)
        {
            int         j0;     /* zeroth day of the ISO year, in Julian */
 
-           j0 = isoweek2j(tmfc.year, 1) - 1;
+           j0 = isoweek2j(tm->tm_year, 1) - 1;
 
            j2date(j0 + tmfc.ddd, &tm->tm_year, &tm->tm_mon, &tm->tm_mday);
        }
        else
        {
-           int        *y,
-                       i;
-
-           int         ysum[2][13] = {
-               {31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365, 0},
-               {31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366, 0}};
+           const int  *y;
+           int         i;
 
-           if (!tm->tm_year)
-               ereport(ERROR,
-                       (errcode(ERRCODE_INVALID_DATETIME_FORMAT),
-                        errmsg("cannot calculate day of year without year information")));
+           static const int ysum[2][13] = {
+               {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
+               {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366}};
 
            y = ysum[isleap(tm->tm_year)];
 
-           for (i = 0; i <= 11; i++)
+           for (i = 1; i <= 12; i++)
            {
-               if (tm->tm_yday < y[i])
+               if (tmfc.ddd < y[i])
                    break;
            }
            if (tm->tm_mon <= 1)
-               tm->tm_mon = i + 1;
+               tm->tm_mon = i;
 
            if (tm->tm_mday <= 1)
-               tm->tm_mday = i == 0 ? tm->tm_yday :
-                   tm->tm_yday - y[i - 1];
+               tm->tm_mday = tmfc.ddd - y[i - 1];
        }
    }
 

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 06eb044f0c5e33ea070e1b72e82ed327f1bcee01..2d1e7ff45aed985854f6000d2bec48b355681214 100644 (file)
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.196 2009/01/01 17:23:50 momjian Exp $
+ *   $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.197 2009/03/15 20:31:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -3668,11 +3668,6 @@ isoweek2j(int year, int week)
    int         day0,
                day4;
 
-   if (!year)
-       ereport(ERROR,
-               (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-          errmsg("cannot calculate week number without year information")));
-
    /* fourth day of current year */
    day4 = date2j(year, 1, 4);