Thread: [PATCH] hstore_to_json: empty hstores must return empty json objects
hstore_to_json used to return an empty string for empty hstores, but
that is not correct as an empty string is not valid json and calling
row_to_json() on rows which have empty hstores will generate invalid
json for the entire row. The right thing to do is to return an empty
json object.
Signed-off-by: Oskari Saarenmaa <os@ohmu.fi>
---
This should probably be applied to 9.3 tree as well as master.
# select row_to_json(r.*) from (select ''::hstore as d) r;{"d":}
# select hstore_to_json('')::text::json;
ERROR: invalid input syntax for type json
contrib/hstore/expected/hstore.out | 12 ++++++++++++contrib/hstore/hstore_io.c | 8
++++----contrib/hstore/sql/hstore.sql | 2 ++3 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/contrib/hstore/expected/hstore.out b/contrib/hstore/expected/hstore.out
index 2114143..3280b5e 100644
--- a/contrib/hstore/expected/hstore.out
+++ b/contrib/hstore/expected/hstore.out
@@ -1472,6 +1472,18 @@ select hstore_to_json_loose('"a key" =>1, b => t, c => null, d=> 12345, e => 012 {"b": true,
"c":null, "d": 12345, "e": "012345", "f": 1.234, "g": 2.345e+4, "a key": 1}(1 row)
+select hstore_to_json('');
+ hstore_to_json
+----------------
+ {}
+(1 row)
+
+select hstore_to_json_loose('');
+ hstore_to_json_loose
+----------------------
+ {}
+(1 row)
+create table test_json_agg (f1 text, f2 hstore);insert into test_json_agg values ('rec1','"a key" =>1, b => t, c =>
null,d=> 12345, e => 012345, f=> 1.234, g=> 2.345e+4'), ('rec2','"a key" =>2, b => f, c => "null", d=> -12345, e
=>012345.6, f=> -1.234, g=> 0.345e-4');
diff --git a/contrib/hstore/hstore_io.c b/contrib/hstore/hstore_io.c
index d3e67dd..3781a71 100644
--- a/contrib/hstore/hstore_io.c
+++ b/contrib/hstore/hstore_io.c
@@ -1241,8 +1241,8 @@ hstore_to_json_loose(PG_FUNCTION_ARGS) if (count == 0) {
- out = palloc(1);
- *out = '\0';
+ out = palloc(3);
+ memcpy(out, "{}", 3); PG_RETURN_TEXT_P(cstring_to_text(out)); }
@@ -1370,8 +1370,8 @@ hstore_to_json(PG_FUNCTION_ARGS) if (count == 0) {
- out = palloc(1);
- *out = '\0';
+ out = palloc(3);
+ memcpy(out, "{}", 3); PG_RETURN_TEXT_P(cstring_to_text(out)); }
diff --git a/contrib/hstore/sql/hstore.sql b/contrib/hstore/sql/hstore.sql
index 68b74bf..47cbfad 100644
--- a/contrib/hstore/sql/hstore.sql
+++ b/contrib/hstore/sql/hstore.sql
@@ -335,6 +335,8 @@ select count(*) from testhstore where h = 'pos=>98, line=>371, node=>CBA, indexeselect
hstore_to_json('"akey" =>1, b => t, c => null, d=> 12345, e => 012345, f=> 1.234, g=> 2.345e+4');select cast( hstore
'"akey" =>1, b => t, c => null, d=> 12345, e => 012345, f=> 1.234, g=> 2.345e+4' as json);select
hstore_to_json_loose('"akey" =>1, b => t, c => null, d=> 12345, e => 012345, f=> 1.234, g=> 2.345e+4');
+select hstore_to_json('');
+select hstore_to_json_loose('');create table test_json_agg (f1 text, f2 hstore);insert into test_json_agg values
('rec1','"akey" =>1, b => t, c => null, d=> 12345, e => 012345, f=> 1.234, g=> 2.345e+4'),
--
1.8.3.1
On Wed, Oct 16, 2013 at 12:02 PM, Oskari Saarenmaa <os@ohmu.fi> wrote: > hstore_to_json used to return an empty string for empty hstores, but > that is not correct as an empty string is not valid json and calling > row_to_json() on rows which have empty hstores will generate invalid > json for the entire row. The right thing to do is to return an empty > json object. Hmm. This sure looks like a bug to me. Anyone think otherwise? -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
On Thu, Oct 17, 2013 at 7:20 AM, Robert Haas <robertmhaas@gmail.com> wrote: > On Wed, Oct 16, 2013 at 12:02 PM, Oskari Saarenmaa <os@ohmu.fi> wrote: >> hstore_to_json used to return an empty string for empty hstores, but >> that is not correct as an empty string is not valid json and calling >> row_to_json() on rows which have empty hstores will generate invalid >> json for the entire row. The right thing to do is to return an empty >> json object. > > Hmm. This sure looks like a bug to me. > > Anyone think otherwise? It is a bug. merlin
On 10/17/2013 08:20 AM, Robert Haas wrote: > On Wed, Oct 16, 2013 at 12:02 PM, Oskari Saarenmaa <os@ohmu.fi> wrote: >> hstore_to_json used to return an empty string for empty hstores, but >> that is not correct as an empty string is not valid json and calling >> row_to_json() on rows which have empty hstores will generate invalid >> json for the entire row. The right thing to do is to return an empty >> json object. > Hmm. This sure looks like a bug to me. > > Anyone think otherwise? > No, you're right. It was a thinko on my part. :-( cheers andrew
Oskari Saarenmaa wrote:
> @@ -1241,8 +1241,8 @@ hstore_to_json_loose(PG_FUNCTION_ARGS)
>
> if (count == 0)
> {
> - out = palloc(1);
> - *out = '\0';
> + out = palloc(3);
> + memcpy(out, "{}", 3);
> PG_RETURN_TEXT_P(cstring_to_text(out));
> }
Can't you just PG_RETURN_TEXT_P(cstring_to_text("{}")) ?
--
Álvaro Herrera http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
Re: [PATCH] hstore_to_json: empty hstores must return empty json objects
From
Oskari Saarenmaa
Date:
On 17/10/13 17:23, Alvaro Herrera wrote:
> Oskari Saarenmaa wrote:
>
>> @@ -1241,8 +1241,8 @@ hstore_to_json_loose(PG_FUNCTION_ARGS)
>>
>> if (count == 0)
>> {
>> - out = palloc(1);
>> - *out = '\0';
>> + out = palloc(3);
>> + memcpy(out, "{}", 3);
>> PG_RETURN_TEXT_P(cstring_to_text(out));
>> }
>
> Can't you just PG_RETURN_TEXT_P(cstring_to_text("{}")) ?
>
I'm not too familiar with PG internals and just modified this to work
like it did before, but it looks like the extra allocation is indeed
unnecessary.
I can post a new patch to make this use cstring_to_text_with_len("{}",
2) (to avoid an unnecessary strlen call) or you can just make the change
and push the modified version.
Thanks, Oskari
On 10/17/2013 10:23 AM, Alvaro Herrera wrote:
> Oskari Saarenmaa wrote:
>
>> @@ -1241,8 +1241,8 @@ hstore_to_json_loose(PG_FUNCTION_ARGS)
>>
>> if (count == 0)
>> {
>> - out = palloc(1);
>> - *out = '\0';
>> + out = palloc(3);
>> + memcpy(out, "{}", 3);
>> PG_RETURN_TEXT_P(cstring_to_text(out));
>> }
> Can't you just PG_RETURN_TEXT_P(cstring_to_text("{}")) ?
>
Yeah. I'm going to fix this this morning.
cheers
andrew