BUG #11121: Error not properly reported when calling PQputCopyData with a column missing

The following bug has been logged on the website:

Bug reference:      11121
Logged by:          Jay Carlson
Email address:      menotyou@gmail.com
PostgreSQL version: 9.3.4
Operating system:   Windows 7 (64 Bit)
Description:

The short version: After successfully calling calling PQexec to COPY_IN from
STDIN, I noticed calling PQputCopyData with a buffer that does not contain
all of the required columns and an incorrectly formatted column, an error is
not generated and PQputCopyEnd will not leave PGRES_COPY_IN mode.  An error
for this situation is only ennunciated after PQputCopyData is called again
AFTER calling PQputCopyEnd.

THE DETAILS:
Here is the format of the status_data table:
++ test_id: integer
++ device_id: integer
++ time_stamp: timestamp with time zone
++ mem_map_detail_id: integer
++ value: text

First I'm successfully calling PQexec with "COPY status_data (test_id,
device_id, time_stamp, mem_map_detail_id, value) FROM STDIN"

----------------------------------
PQputCopyData 1: (No error expected)
If I call PQputCopyData with the following the result is 1 (Success):
"1\t3\t07/25/2014\t48811\tHey1\n"

At this point after calling PQgetResult:
PQresultStatus returns 4 (PGRES_COPY_IN)
PQerrorMessage returns no error.

----------------------------------
PQputCopyData 2: (Expected Error)
If I call PQputCopyData with the following (missing the tab before "Hey2"),
the result is 1 (Success):
"1\t3\t07/25/2014\t48811Hey2\n"

At this point after calling PQgetResult:
PQresultStatus returns 4 (PGRES_COPY_IN)
PQerrorMessage returns no error.

**An error should have been generated here because we are calling
PQputCopyData with the incorrect number of columns AND an incorrect format
for one of the columns.

----------------------------------
PQputCopyData 3: (No error expected)
If I call PQputCopyData with the following the result is 1 (Success):
"1\t3\t07/25/2014\t48811\tHey3\n"

At this point after calling PQgetResult:
PQresultStatus returns 4 (PGRES_COPY_IN)
PQerrorMessage returns no error.

** There is STILL no error generated!

----------------------------------
If I then call PQputCopyEnd it returns 1 (Success) and an error message =
(null).

At this point after calling PQgetResult:
PQresultStatus returns 4 (PGRES_COPY_IN)

So far no error has been returned at all but PQputCopyEnd did not leave the
PGRES_COPY_IN state.

----------------------------------
PQputCopyData 4:
Now, AFTER CALLING PQputCopyEnd, if I call PQputCopyData with the following
valid buffer string I FINALLY see an error even though the string I'm
sending is kosher:
"1\t3\t07/25/2014\t48811\tHey4\n"

At this point after calling PQgetResult:
PQresultStatus returns 7 (PGRES_FATAL_ERROR)
PQerrorMessage returns:
'ERROR:  invalid input syntax for integer: "48811Hey2"
CONTEXT:  COPY status_data, line 2, column mem_map_detail_id: "48811Hey2"'