Float value 'Infinity' is cast to numeric 1 on Windows
Hi all,
I build PostgreSQL 9.6.5 by Visual Studio 2013 on Windows, I found weird behavior on it.
I execute following SQL, occurring ERROR is expected, but I got mysterious value 1.
postgres=# select (float8 'inf')::numeric;
numeric
---------
1
(1 row)
On Windows, at least Visual Studio, the string of float/double value meaning
infinity is "1.#INF" not "inf". So, set_var_from_str() called from float8_numeric()
in utils/adt/numeric.c will return numeric value 1, and no one checks this situation.
This situation is also occurring by cast from float4.
I wrote a patch to add check this situation.
Please find attached.
Sincerely,
--
Taiki Kondo
NEC Solution Innovators, Ltd.
Attachments:
fix_infinity_to_1.patchapplication/octet-stream; name=fix_infinity_to_1.patchDownload
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index ddc44d5179..e871b94bb8 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -3139,6 +3139,7 @@ float8_numeric(PG_FUNCTION_ARGS)
Numeric res;
NumericVar result;
char buf[DBL_DIG + 100];
+ char *cp;
if (isnan(val))
PG_RETURN_NUMERIC(make_result(&const_nan));
@@ -3148,7 +3149,14 @@ float8_numeric(PG_FUNCTION_ARGS)
init_var(&result);
/* Assume we need not worry about leading/trailing spaces */
- (void) set_var_from_str(buf, buf, &result);
+ cp = set_var_from_str(buf, buf, &result);
+
+ /* We have to check if val is invalid actually. */
+ if (*cp)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ errmsg("invalid input syntax for type %s: \"%s\"",
+ "numeric", buf)));
res = make_result(&result);
@@ -3205,6 +3213,7 @@ float4_numeric(PG_FUNCTION_ARGS)
Numeric res;
NumericVar result;
char buf[FLT_DIG + 100];
+ char *cp;
if (isnan(val))
PG_RETURN_NUMERIC(make_result(&const_nan));
@@ -3214,7 +3223,14 @@ float4_numeric(PG_FUNCTION_ARGS)
init_var(&result);
/* Assume we need not worry about leading/trailing spaces */
- (void) set_var_from_str(buf, buf, &result);
+ cp = set_var_from_str(buf, buf, &result);
+
+ /* We have to check if val is invalid actually. */
+ if (*cp)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ errmsg("invalid input syntax for type %s: \"%s\"",
+ "numeric", buf)));
res = make_result(&result);
Hello,
Does it make sense to put a check of "isinf(val)" and ereport prior to
the snprintf()?
It is a lightweight check more than set_var_from_str().
Thanks,
2017-09-27 19:41 GMT+09:00 Taiki Kondo <tai-kondo@yk.jp.nec.com>:
Hi all,
I build PostgreSQL 9.6.5 by Visual Studio 2013 on Windows, I found weird behavior on it.
I execute following SQL, occurring ERROR is expected, but I got mysterious value 1.
postgres=# select (float8 'inf')::numeric;
numeric
---------
1
(1 row)On Windows, at least Visual Studio, the string of float/double value meaning
infinity is "1.#INF" not "inf". So, set_var_from_str() called from float8_numeric()
in utils/adt/numeric.c will return numeric value 1, and no one checks this situation.This situation is also occurring by cast from float4.
I wrote a patch to add check this situation.
Please find attached.Sincerely,
--
Taiki Kondo
NEC Solution Innovators, Ltd.--
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--
HeteroDB, Inc / The PG-Strom Project
KaiGai Kohei <kaigai@heterodb.com>
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Kohei KaiGai <kaigai@heterodb.com> writes:
Does it make sense to put a check of "isinf(val)" and ereport prior to
the snprintf()?
Yeah, that was my reaction too. Obviously this wasn't thought about
in the original coding ...
regards, tom lane
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