diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/utils/adt/numeric.c | 33 | ||||
| -rw-r--r-- | src/test/regress/expected/float8.out | 6 | ||||
| -rw-r--r-- | src/test/regress/sql/float8.sql | 2 |
3 files changed, 25 insertions, 16 deletions
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c index defdc623cdc..a8cd22611d3 100644 --- a/src/backend/utils/adt/numeric.c +++ b/src/backend/utils/adt/numeric.c @@ -14,7 +14,7 @@ * Copyright (c) 1998-2008, PostgreSQL Global Development Group * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.111 2008/05/08 19:25:38 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.112 2008/05/08 22:17:54 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -5170,21 +5170,6 @@ power_var(NumericVar *base, NumericVar *exp, NumericVar *result) int local_rscale; double val; - /* - * This avoids log(0) for cases of 0 raised to a non-integer. - * Also, while 0 ^ 0 can be either 1 or indeterminate (error), we - * treat it as one because most programming languages do this. - * http://en.wikipedia.org/wiki/Exponentiation#Zero_to_the_zero_power - */ - if (cmp_var(base, &const_zero) == 0) - { - if (cmp_var(exp, &const_zero) == 0) - set_var_from_var(&const_one, result); - else - set_var_from_var(&const_zero, result); - return; - } - /* If exp can be represented as an integer, use power_var_int */ if (exp->ndigits == 0 || exp->ndigits <= exp->weight + 1) { @@ -5217,6 +5202,17 @@ power_var(NumericVar *base, NumericVar *exp, NumericVar *result) free_var(&x); } + /* + * This avoids log(0) for cases of 0 raised to a non-integer. + * 0 ^ 0 handled by power_var_int(). + */ + if (cmp_var(base, &const_zero) == 0) + { + set_var_from_var(&const_zero, result); + result->dscale = NUMERIC_MIN_SIG_DIGITS; /* no need to round */ + return; + } + init_var(&ln_base); init_var(&ln_num); @@ -5284,6 +5280,11 @@ power_var_int(NumericVar *base, int exp, NumericVar *result, int rscale) switch (exp) { case 0: + /* + * While 0 ^ 0 can be either 1 or indeterminate (error), we + * treat it as 1 because most programming languages do this. + * http://en.wikipedia.org/wiki/Exponentiation#Zero_to_the_zero_power + */ set_var_from_var(&const_one, result); result->dscale = rscale; /* no need to round */ return; diff --git a/src/test/regress/expected/float8.out b/src/test/regress/expected/float8.out index 38d2cbfb417..f81d9b2bac0 100644 --- a/src/test/regress/expected/float8.out +++ b/src/test/regress/expected/float8.out @@ -349,6 +349,12 @@ SELECT '' AS bad, f.f1 * '1e200' from FLOAT8_TBL f; ERROR: value out of range: overflow SELECT '' AS bad, f.f1 ^ '1e200' from FLOAT8_TBL f; ERROR: value out of range: overflow +SELECT 0 ^ 0 + 0 ^ 1 + 0 ^ 0.0 + 0 ^ 0.5; + ?column? +---------- + 2 +(1 row) + SELECT '' AS bad, ln(f.f1) from FLOAT8_TBL f where f.f1 = '0.0' ; ERROR: cannot take logarithm of zero SELECT '' AS bad, ln(f.f1) from FLOAT8_TBL f where f.f1 < '0.0' ; diff --git a/src/test/regress/sql/float8.sql b/src/test/regress/sql/float8.sql index b4dd7be4b3f..92b6b0d7b96 100644 --- a/src/test/regress/sql/float8.sql +++ b/src/test/regress/sql/float8.sql @@ -129,6 +129,8 @@ SELECT '' AS bad, f.f1 * '1e200' from FLOAT8_TBL f; SELECT '' AS bad, f.f1 ^ '1e200' from FLOAT8_TBL f; +SELECT 0 ^ 0 + 0 ^ 1 + 0 ^ 0.0 + 0 ^ 0.5; + SELECT '' AS bad, ln(f.f1) from FLOAT8_TBL f where f.f1 = '0.0' ; SELECT '' AS bad, ln(f.f1) from FLOAT8_TBL f where f.f1 < '0.0' ; |