Re: [Bug fix] PQsendQuery occurs error when target_session_attrs is set to read-write

On Thu, Feb 2, 2017 at 1:34 PM, Ashutosh Bapat
<ashutosh(dot)bapat(at)enterprisedb(dot)com> wrote:
> On Thu, Feb 2, 2017 at 10:04 AM, Ashutosh Bapat
> <ashutosh(dot)bapat(at)enterprisedb(dot)com> wrote:
>> [1] https://www.postgresql.org/docs/devel/static/libpq-exec.html: PQgetvalue().
> The code expects that there will be two PQgetResult() calls required.
> One to fetch the result of SHOW command and the other to extract NULL.
> If we require more calls or unexpected results, we should throw and
> error. The patch just checks the first result and consumes the
> remaining without verifying them. Also, it looks like we can not clear
> result of PQgetResult() before using the values or copying them
> somewhere else [1]. Here's updated patch which tries to do that.
> Please let me know if this looks good to you.

This has not been added yet to the next CF. As Ashutosh mentioned
things tend to be easily forgotten. So I have added it here:
https://commitfest.postgresql.org/13/982/

I have noticed this typo on the way => s/requisted/requested/:
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -2908,7 +2908,7 @@ keep_going: /* We will
come back to here until there is
}

/*
- * If a read-write connection is requisted check for same.
+ * If a read-write connection is requested check for same.
*/
if (conn->target_session_attrs != NULL &&
strcmp(conn->target_session_attrs, "read-write") == 0)

Looking at the patch, I agree with Ashutosh. Any fix should be located
in the code path of CONNECTION_CHECK_WRITABLE which is the one
consuming the results.
--
Michael