pool (2026.08.31.2)
Two more found by fuzzing rather than by users, outside the type system.
Both are ordinary-path bugs a happy-path test cannot reach.
A failed statement was never released. Successful DML sent PREPARE ->
EXECUTE -> RELEASE; failing DML sent PREPARE -> EXECUTE and stopped. The
statement stayed allocated server-side, collided with the next PREPARE,
and every subsequent call on that connection returned a nonsense error
(-255 "Not in transaction" under autocommit, -285 otherwise) whose
offset pointed back at the FAILED sql rather than the new statement.
In practice: one duplicate-key violation bricked the connection. An
INSERT tripping a unique constraint is about the most routine error an
application can hit — every insert-if-not-exists pattern makes them —
and afterwards nothing on that connection worked.
The docstring on the parameterised path already described this hazard
and guarded the parameter-ENCODING failure; it never covered EXECUTE
itself failing. Fixed in all three paths (DML, parameterised DML, and
SELECT — whose fetch loop had the same gap, and whose GC-time finalizer
only covers scrollable cursors).
Cancelling a pool acquire leaked the connection permanently.
asyncio.to_thread cannot interrupt its worker, so a task cancelled while
blocked in pool.acquire() left the worker to finish and hand back a
connection nobody owned — checked out, never returned, one slot gone per
occurrence until the pool was dead.
Not theoretical for anything serving HTTP: a client disconnect cancels
the request task, and under load those cancellations land precisely
while waiting for a connection. The pool dies one slot at a time, only
under load, and PoolTimeoutError points nowhere near the cause.
acquire() now shields the inner future and returns whatever the worker
produced if the caller went away; add_done_callback fires immediately on
an already-resolved future, so the "worker finished just before the
cancel" race is the same code path rather than a second one.
The harness covered three things the type fuzzer cannot see: fetch
batching (NFETCH is a 4096-BYTE budget, so batch edges move with row
width — counts 0..1025 across three schema widths, every fetch style
required to agree), error recovery (eight error classes, repeated, each
followed by a known-good query on the same cursor and a fresh one), and
concurrency (threads sharing one connection, pooled threads that fail
before releasing, transaction isolation across checkouts, async
cancellation). Every worker reads back a value only it supplied, so a
crossed wire fails on data even when nothing raises.
Two harness false positives worth recording: Informix silently truncates
over-long strings (a literal SQL insert does the same, so the driver
matches the server), and it rejects a bare `?` in a projection — a cast
is required.
356/356 integration on 15, 14.10 and 12.10 (was 326).
Six framing bugs had reached users across three reports. Rather than
wait for a seventh, this adds a harness built to find that class of bug.
It immediately found three more, one of which hangs the connection.
BOOLEAN could not be bound as a parameter at all. _encode_bool emitted
type code 45, which the server does not accept as a bind type — it
simply stopped responding, so any execute() with a bool parameter hung
until the read timeout, or forever without one. Type 41 (how BOOLEAN is
*described* in results) hangs identically; descriptor type and bind type
are not interchangeable. Now binds 't'/'f' as CHAR and lets the server
cast, mirroring Informix's own literal syntax. A hang is worse than
wrong data, and this shipped in every release claiming BOOLEAN support.
Unscaled DECIMAL was read one byte short, shifting every following
column. Width is (precision + (scale & 1) + 3) // 2 per
IfxColumnInfo.adjustedColumnLength; we dropped the `scale & 1` term.
That only matters when precision is even and scale is odd — and an
unscaled DECIMAL(p) reports scale 255. DECIMAL(16) is 10 bytes, not 9.
Verified on the wire for ten DECIMAL/MONEY shapes. The same formula
governs DATETIME and INTERVAL, whose qualifier parity tracks their digit
count, so those agreed by coincidence; all four now share one helper
taken from the reference.
NULL CHAR/NCHAR came back as '', indistinguishable from an empty column,
so `WHERE c IS NULL` disagreed with what the driver returned. The wire
distinguishes them plainly — NULL is a leading 0x00, empty is all
spaces.
The harness (tests/test_type_matrix.py) encodes three principles, each
derived from how a real bug escaped:
1. Always put a column after the value under test. Every bug so far
corrupted the NEXT column; a trailing value can be mis-sized
invisibly. Every case ends in a sentinel, and projections rotate.
2. Vary the data, not just the type. Branch coverage is worthless if
no value takes the branch — the LVARCHAR fixture was 'lv value',
8 chars, even, never NULL, so both broken branches sat unexecuted
through 247 tests.
3. Use an oracle our codecs don't share. A Python round-trip cannot
catch a symmetric encode/decode bug: our DATETIME encoder wrote
zeros and our decoder read them back in perfect agreement. Asking
the server to render the stored value breaks that symmetry.
Exhaustive over the corpus plus seeded random multi-type rows, so
failures reproduce.
326/326 integration on 15, 14.10 and 12.10 (was 281). Fuzzer reports
clean over 80-round runs at several seeds and widths on all three.
More data corruption from the same field report as 2026.05.08.2. Anyone
with LVARCHAR columns should upgrade: 2026.08.27 is not safe for them.
Two independent errors in the LVARCHAR envelope, both shifting every
column selected after it.
1. A phantom pad byte. We appended an even-byte pad when the value
length was odd. There is no pad. Wire capture (12.10), INT8 /
LVARCHAR / INT8:
00 01 00 00 07 d1 00 00 00 00 a = INT8 2001
00 null indicator
00 00 00 0b length 11
50 61 63 6b 61 67 65 52 6f 6f 74 "PackageRoot" (odd)
00 01 00 00 00 0a 00 00 00 00 b = INT8 10, starts immediately
2. A missing length on NULL. We returned as soon as the indicator said
NULL, leaving its 4-byte length unread. The length belongs to the
envelope and is always present:
'odd' -> 00 | 00 00 00 03 | 6f 64 64 8 bytes
NULL -> 01 | 00 00 00 00 5 bytes
'' -> 00 | 00 00 00 00 5 bytes
NULL and empty string differ only in the indicator byte.
Reported symptom: INT8 10 decoding as 2560 (the same value shifted one
byte left), strings losing their first character, and IndexError or
"INT8 payload too short" once the drift ran off the payload. The
reporter isolated it by reordering columns in the projection — right
when first, wrong when later. That's the fingerprint of positional
drift and a genuinely good diagnostic.
Missed by 247 tests because the only LVARCHAR fixture was 'lv value':
8 characters, even, never NULL. Neither faulty branch ever ran. Same
gap shape as last time — code paths covered, the data reaching them
not. New tests vary parity (0,1,2,3,11,255,256), cover NULL and empty
separately, always place a column AFTER the LVARCHAR, and rotate the
projection through every position.
Separately, DATETIME lost sub-second precision on INSERT. The encoder
emitted YEAR TO SECOND unconditionally, so binding a datetime with
microseconds into a FRACTION(n) column stored zeros, silently. Reads
were always right, so it only went missing on the way in. Now widens
to FRACTION(5) when microsecond is non-zero and keeps the original
encoding otherwise, so the well-exercised path stays byte-identical.
Binding into a narrower column still truncates server-side.
Also: server_version reported 9.56 for a 12.10 server, which reads like
a client-SDK version. The login response only carries the internal
protocol version, and documenting that didn't make the name less
misleading. server_version now returns the release via one cached
DBINFO query; server_version_internal returns the raw login string.
281/281 integration on 15, 14.10 and 12.10; 123 unit tests.
Auditing the docs site against the actual module surface — prompted by
the same field report as 2026.05.08.2 — turned up a partly fictional API.
Every claim below was checked by calling it, not by reading the source.
Documented but nonexistent, now removed:
conn.transaction() AttributeError (neither sync nor async)
conn.autocommit never existed; set via connect(autocommit=)
cursor.lastrowid never existed
cursor.read_clob_column never existed
cursor.write_clob_column never existed
A copy-pasteable example in reference/types.md raised TypeError:
IntervalYM takes a single total month count, not (years=, months=).
False descriptions corrected: RowValue was described as "named-tuple-like
with .name-accessible fields" and CollectionValue as "iterable" with
"indexed access". Neither is true — both are opaque wrappers over raw
bytes plus a schema string. The docs now say so and point at SQL
projection as the way to get fields today.
Replacements are the real idioms, taken from passing tests:
CLOBs -> write_blob_column(..., clob=True); read returns bytes
SERIAL value -> SELECT DBINFO('sqlca.sqlerrd1')
transactions -> commit()/rollback() in try/except
Also added: INT8/SERIAL8/BIGSERIAL to the type table (with why INT8 is
not BIGINT), server_capabilities + server_version, the scrollable-cursor
methods, and the note that server_version reports the internal protocol
version (12.10 says 9.56, 14.10 says 9.59).
Updated the test-count claim to 400+ across three server versions,
replacing "integration tests run against 15.0.1.0.3DE".
Added a checker pass over every conn.*/cursor.* reference in the docs;
the only remaining unresolved names are deliberate mentions of IfxPy
APIs we don't implement. Site builds clean.
Previously the horizontal-scroll fallback only applied at ≤640px; between
641px and 799px (tablet portrait, narrow desktop 2-col), the hero stayed
2-column so the wire-dump column could still be too narrow for the
~564px hex content, and overflow: hidden silently clipped the right side.
Lifting overflow-x: auto to all widths means: (a) any width where the
column is wider than the hex, content displays normally with no scroll;
(b) any width where the column is narrower, content becomes
horizontally-scrollable inside the dump. y stays hidden to keep the
typed-out animation's unrevealed lines clipped below the fold.
Root cause: hero's grid items inherited min-width: auto, so the wire-dump's
white-space: pre hex lines (~564px wide content) forced the hero column to
that width, propagating up to the page and causing 193px of horizontal
overflow at narrow viewports.
Fix:
- min-width: 0 on .ifx-hero, .ifx-hero__copy, .ifx-hero__visual (lets
grid items shrink below content's intrinsic min-width)
- overflow-x: auto on .ifx-wiredump (contains residual hex overflow
inside the dump, not on the page)
- Font shrunk 0.78rem → 0.62rem on mobile, ASCII column hidden, padding
tightened — readable hex without horizontal scroll inside the dump
- Eyebrow flex-wrap: wrap so the No-libcrypt suffix wraps cleanly
- Title floor 2rem → 1.75rem at 7.5vw for narrow screens
- Tightened CTA padding, install command word-break: break-all
Sweep all backticked + bold + table-cell + heading mentions of the
project's brand to match the PyPI distribution name and the docs domain.
Path references (`cd informix-db`, `git.supported.systems/.../informix-db`)
stay — those reference the actual Gitea repo directory which we did NOT
rename. Same with `import informix_db` (Python module name, separate
from distribution brand).
Also flip GitHub references to Gitea throughout the docs site:
- `github.com/rsp2k/informix-db/blob/main/X` → Gitea `/src/branch/main/X`
- `github.com/rsp2k/informix-db/tree/main/X` → Gitea same path
- `github.com/rsp2k/informix-db` (plain) → Gitea
- Hero "GitHub" CTA button → Gitea source URL
- Social icon: `github` → `seti:git` (generic git icon, not octocat)
Net result: zero stale GitHub references, brand consistency matches what
users `pip install`.
Match what users see when they `pip install informix-driver`. Also fix
two broken social links: PyPI was pointing at the now-404 informix-db
project, GitHub link was pointing at github.com/rsp2k/informix-db
(repo doesn't exist there — source lives on Gitea). Rewired to:
- Source (Gitea): git.supported.systems/warehack.ing/informix-db
- PyPI: pypi.org/project/informix-driver
- editLink: Gitea's _edit/branch/main URL pattern
Logo SVG aria-label + title also updated for accessibility consistency.
