Message-ID: <gh-postgresql-interfaces-psqlodbc-178@github.com>
From: "jarvis24young (@jarvis24young)" <noreply+jarvis24young@github.com>
To: "postgresql-interfaces/psqlodbc" <noreply+postgresql-interfaces-psqlodbc@github.com>
Date: Tue, 28 Apr 2026 03:26:23 +0000
Subject: [postgresql-interfaces/psqlodbc] PR #178: Reject overlong cursor names
List-Id: <gh-postgresql-interfaces-psqlodbc.github.com>
X-GitHub-Author-Id: 48787405
X-GitHub-Author-Login: jarvis24young
X-GitHub-Issue: 178
X-GitHub-Repo: postgresql-interfaces/psqlodbc
X-GitHub-State: merged
X-GitHub-Type: pull_request
X-GitHub-Url: https://github.com/postgresql-interfaces/psqlodbc/pull/178
Content-Type: text/plain; charset=utf-8

## Summary

This patch makes `SQLSetCursorName()` reject cursor names longer than the length advertised by the driver through `SQLGetInfo(SQL_MAX_CURSOR_NAME_LEN)`.

The driver reports `MAX_CURSOR_LEN` (`32`) for `SQL_MAX_CURSOR_NAME_LEN`, but `PGAPI_SetCursorName()` previously accepted and stored longer application-provided cursor names. The new check validates the fully materialized cursor name before replacing the statement's current cursor name.

## Details

`PGAPI_SetCursorName()` now:

- builds the requested cursor name into a temporary buffer first;
- reports `STMT_NO_MEMORY_ERROR` if allocation fails;
- rejects names longer than `MAX_CURSOR_LEN` with `STMT_INVALID_CURSOR_NAME`;
- only replaces `stmt->cursor_name` after allocation and validation both succeed.

This keeps the statement state unchanged on failure and makes `SQLSetCursorName()` consistent with the driver's advertised ODBC cursor-name limit.

## Regression test

The existing `cursor-name` black-box ODBC test now:

- queries `SQL_MAX_CURSOR_NAME_LEN` from the connected driver;
- builds an invalid cursor name with length `SQL_MAX_CURSOR_NAME_LEN + 1`;
- verifies that `SQLSetCursorName()` rejects it;
- verifies the diagnostic SQLSTATE is `34000`;
- then continues through the existing valid cursor-name path.

Verified in WSL against the unixODBC test path with an ASan/UBSan/gcov build:

```sh
cd ~/psqlodbc-build
make -j4
cd test
make LIBODBC='-lodbc' exe/cursor-name-test
ODBCSYSINI=. ODBCINSTINI=./odbcinst.ini ODBCINI=./odbc.ini \
  ASAN_OPTIONS=verify_asan_link_order=0:detect_leaks=0 \
  LD_PRELOAD=/lib/x86_64-linux-gnu/libasan.so.8 \
  ./runsuite cursor-name --inputdir=.
```

Result:

```text
TAP version 13
1..1
ok 1 - cursor-name
```