Don't fail on libpq-generated error reports in ecpg_raise_backend().

An error PGresult generated by libpq itself, such as a report of
connection loss, won't have broken-down error fields.
ecpg_raise_backend() blithely assumed that PG_DIAG_MESSAGE_PRIMARY
would always be present, and would end up passing a NULL string
pointer to snprintf when it isn't.  That would typically crash
before 3779ac62d, and it would fail to provide a useful error report
in any case.  Best practice is to substitute PQerrorMessage(conn)
in such cases, so do that.

Per bug #17421 from Masayuki Hirose.  Back-patch to all supported
branches.

Discussion: https://postgr.es/m/17421-790ff887e3188874@postgresql.org
This commit is contained in:
Tom Lane 2022-06-06 11:20:21 -04:00
parent 157f8739ad
commit 6d157e7cb8
1 changed files with 9 additions and 10 deletions

View File

@ -229,18 +229,17 @@ ecpg_raise_backend(int line, PGresult *result, PGconn *conn, int compat)
return;
}
if (result)
{
sqlstate = PQresultErrorField(result, PG_DIAG_SQLSTATE);
if (sqlstate == NULL)
sqlstate = ECPG_SQLSTATE_ECPG_INTERNAL_ERROR;
message = PQresultErrorField(result, PG_DIAG_MESSAGE_PRIMARY);
}
else
{
/*
* PQresultErrorField will return NULL if "result" is NULL, or if there is
* no such field, which will happen for libpq-generated errors. Fall back
* to PQerrorMessage in such cases.
*/
sqlstate = PQresultErrorField(result, PG_DIAG_SQLSTATE);
if (sqlstate == NULL)
sqlstate = ECPG_SQLSTATE_ECPG_INTERNAL_ERROR;
message = PQresultErrorField(result, PG_DIAG_MESSAGE_PRIMARY);
if (message == NULL)
message = PQerrorMessage(conn);
}
if (strcmp(sqlstate, ECPG_SQLSTATE_ECPG_INTERNAL_ERROR) == 0)
{