Message-ID: <gh-postgresql-interfaces-psqlodbc-175-c4303214448@github.com>
From: "jarvis24young (@jarvis24young)" <noreply+jarvis24young@github.com>
To: "postgresql-interfaces/psqlodbc" <noreply+postgresql-interfaces-psqlodbc@github.com>
Date: Thu, 23 Apr 2026 09:18:52 +0000
Subject: Re: [postgresql-interfaces/psqlodbc] PR #175: Validate percent escapes before decoding connection-string values
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I updated the regression test to make it stronger.

Instead of using `PWD=...` and accepting an authentication failure, the test now uses `pqopt=application_name=...`. That still exercises the same `decode_or_remove_braces()` / `decode()` path for connection-string percent decoding, but it does not override the DSN password, so `SQLDriverConnect()` is expected to succeed for each case.

For reference, before this patch the truncated percent case triggers UBSan in my local ASan/UBSan build:

```text
dlg_specific.c:1584:12: runtime error: left shift of negative value -48
    #0 conv_from_hex /home/yjw/psqlodbc-build/dlg_specific.c:1584
    #1 decode /home/yjw/psqlodbc-build/dlg_specific.c:1612
    #2 decode_or_remove_braces /home/yjw/psqlodbc-build/dlg_specific.c:1658
    #3 copyConnAttributes /home/yjw/psqlodbc-build/dlg_specific.c:639
    #4 dconn_get_attributes /home/yjw/psqlodbc-build/drvconn.c:577
    #5 PGAPI_DriverConnect /home/yjw/psqlodbc-build/drvconn.c:157
    #6 SQLDriverConnect /home/yjw/psqlodbc-build/odbcapi.c:213
```

The `ok` output in the committed regression test represents the fixed behavior: malformed percent escapes no longer reach `conv_from_hex()`, and the connection path completes successfully.