BUG #9776: well formed json with embedd colon ':' causes error on copy

The following bug has been logged on the website:

Bug reference: 9776
Logged by: Larry Price
Email address: larry(dot)price(at)enterprisedb(dot)com
PostgreSQL version: 9.3.3
Operating system: CENTOS
Description:

using a simple table with json datatype

Table "test.testset"
Column | Type | Modifiers
--------+------+-----------
tune | json |

attempt to insert the following json (well formed according to jq, python
simplejson and other parsers

---
{
"title": "Rinaldo : Act 1 \"Cor ingrato, ti rammembri\" [Rinaldo]",
"track_id": "TRBBIYX128F1497FF2",
"tags": [],
"similars": [],
"timestamp": "2011-09-14 11:38:47.924559",
"artist": "Marilyn Horne"
}
___

attempting to insert using psql \copy

results:

psql -U test -d test -c '\copy testset (tune) from stdin'
ERROR: invalid input syntax for type json
DETAIL: Token "Cor" is invalid.
CONTEXT: JSON data, line 1: ...BBIYX128F1497FF2", "title": "Rinaldo : Act 1
"Cor...
COPY testset, line 1, column tune: "{"artist": "Marilyn Horne", "timestamp":
"2011-09-14 11:38:47.924559", "similars": [], "tags": [], "..."

it seems to be stripping the escape sequences before the json is parsed.
Could be user error. But it appears that strings are not getting escaped
properly before being parsed as json, but only when the copy statement is
used. Other json from the same set gets properly inserted.

using insert with the same value works
---
insert into testset (tune) values ('{
"title": "Rinaldo : Act 1 \"Cor ingrato, ti rammembri\" [Rinaldo]",
"track_id": "TRBBIYX128F1497FF2",
"tags": [],
"similars": [],
"timestamp": "2011-09-14 11:38:47.924559",
"artist": "Marilyn Horne"
}' );
---