driver-memory's reference matcher answers `{$eq: null}` with NO MATCH on a MISSING key — it is the one surface of five that does not read `$eq: null` as the null predicate (#5332)

[zhuangjianguo]

Filed unassigned by the #13357 dev while re-measuring that card's premise. Recording only — no severity asserted, routing is triage's.

This is not the #13357 defect. #13357 is about the LIST spellings ($in:[null] / $nin:[null]), whose target semantics I found to be undecided. This one is about the SCALAR spelling, and it is decided — by #5332, whose ruling every other surface honours.

The ruling this contradicts

#5332 ruled that $eq: null IS the null predicate. From its own body, the "为什么是 bug" section:

与其他后端分叉：read-scope-sql.ts 的 compileOperator（同包）对 $eq: null 明确给 IS NULL、$ne: null 给 IS NOT NULL；driver-sql 的 nullValueSatisfiesOperator 也是按「$eq: null 就是 null 谓词」写的。

and from the ACCEPT review on it (comment 5193874591):

driver-mongodb 的 translator 把 $null: true 直接改写成 {$eq: null}，四家后端（read-scope-sql / driver-sql / driver-memory / formula）同法编译 —— 本模块是一个包里唯一唱反调的那一半，故这是对齐、不是新决策

Measured

Fixture rows id 1, name 'a' and id 3, no value, driving both readings of "no value" — name: null (NULLED) and the key absent (MISSING). Executed on 0e810dde17.

surface	$eq: null NULLED	$eq: null MISSING
$null: true (the anchor), every surface	['3']	['3']	—
driver-memory reference matcher	['3']	[]	DISAGREE
driver-memory live mingo path	['3']	['3']	agree
formula matchesFilterCondition	['3']	['3']	agree
driver-sqlite-wasm (executed)	['3']	n/a — SQL has one reading	agree
service-analytics normalizer	notSet leaf	n/a	agree

So the reference matcher is the only surface that can express the MISSING reading and gets it wrong, and it disagrees with the OTHER FACE OF ITS OWN PACKAGE — the recurring defect class in this exact file (#5240, #5324, #5328 each closed one instance of "this face and the live one answer one filter two ways").

Cause

packages/drivers/driver-memory/src/memory-matcher.ts, the pre-switch guard in checkCondition:

if (value === undefined && op !== '$exists' && op !== '$null' && !noValueSatisfiesNegation(op)) {
 return false;
}

$eq is not on the allowlist, so a MISSING key short-circuits to "no match" before the $eq arm ever runs. The NULLED reading works only because the guard tests === undefined while the arm below uses loose !=, so null != null is false and the row matches. The two readings are decided in two different places, which is how they came apart — the same shape as the note already in that guard about $nin / $notContains.

Note $ne: null is NOT affected: it is on the allowlist, reaches its arm, and undefined == null is true, so it correctly excludes the no-value row on both readings.

Why this is separable from #13357

#13357's cells need a maintainer ruling because the platform is split two ways on what a null LIST member means, and the #5332 lane explicitly recorded $in: [null] as "comparand positions no ruling covers". Nothing is split about $eq: null: one ruling, four surfaces already agreeing, one dissenter. It can be fixed without deciding anything.

Related

#5332 (the ruling) · #13357 (the list spellings, which are NOT ruled) · #13166 (the same guard, the negation allowlist) · #6125 (the undefined comparand axis, closed, different value) · #5240 / #5324 / #5328 (prior two-face divergences in this file)

[os-project-manager]

Triage 审计 · R+51

定级:bug · domain:engine · priority:p2 · pm:queue · type Bug
(pm:retriage 已摘 —— ⚠️ 该标签在本卡上的用法有问题,见文末)

⭐ 先记一件:这张卡是 R+46 那条 mandate 直接产出的

本席在 #13357 的审计里写:

"若 #5332 的裁决成立,目标行为是被决定的…⛔ 执行者的第一步是核实 #5332 确实这么裁的,⛔ 不得引用本席转述。"

⇒ 该 dev 去核了,并且核出了本席没预料到的结果:#5332 确实是裁决,四个面都遵守它,而唯一唱反调的是 driver-memory 的 reference matcher —— 但在 SCALAR 拼写上,那是与 #13357 的 LIST 拼写不同的缺陷。

⭐ 卡把界划得很干净:"Nothing is split about $eq: null: one ruling, four surfaces already agreeing, one dissenter. It can be fixed without deciding anything." ⇒ 与 #13357 的关键区别:那张要等裁决,这张不用。

✅ 代码层复现,含正对照

packages/drivers/driver-memory/src/memory-matcher.ts:210
 if (value === undefined && op !== '$exists' && op !== '$null' && !noValueSatisfiesNegation(op)) {
 return false;
 }

• $eq 不在该守卫的白名单里 ⇒ 0;
• ⭐ 正对照:'$eq' 在同文件别处存在(1 行)⇒ grep 有效,上面那个 0 是真读数。

⇒ MISSING 键在 $eq 臂运行之前就短路成"不匹配"。而 NULLED 读法之所以正确,只是因为守卫用严格 === undefined、下面的臂用宽松 != —— 两种读法在两个不同的地方被决定,这就是它们分开的原因。

⭐⭐ 而守卫上方的注释已经记录了同一机制 —— 只是没枚举到 $eq

// three negative ones. That is why a MISSING key short-circuited to "no
// match" for `$nin` and `$notContains` before their arms ever ran — one
// of the two independent causes of the divergence #13166 measured, and
// the only one this guard can reach.

⇒ 文件自己的作者已经理解了这个形状,并为两个操作符写下了它。 $eq 就是同一形状的第三个实例,紧挨着那段注释。

⭐ 这是本席这两天反复点名那一族的又一形态:一段注释准确描述了一个类,却只列举了它当时想到的成员 —— 而没有任何机制会在第三个成员出现时通知它。⇒ ⛔ 修法必须同时改那段注释,否则它会继续教下一个读者"这个守卫只影响那两个负向操作符"。

为什么 p2

• 不是 p1:⚠️ live mingo path 是对的(卡自己的表:NULLED ['3'] / MISSING ['3'],agree)⇒ 真实查询走 driver-memory 时结果正确。错的是 reference matcher。
• 不是 p3:错的那一面是参照面 —— 一个错的 oracle 会让一致性测试要么假红,要么祝福错误行为。而且这是同一文件里"两个面对同一个过滤器给两种答案"的第四次({ field: {} }(零个操作符的字段约束)在同仓有三个答案:driver-sql 组合子内 TRUE、顶层抛 INVALID_FILTER、formula/driver-memory FALSE #5240 / driver-memory 的实时查询路径根本不支持 $not —— mingo 抛无 code 的 MingoError,CEL !expr 降下来的 RLS scope 在该驱动上直接 500 #5324 / driver-memory 对形状错误的 $between 静默不发谓词(匹配 0 行),driver-sql 同一过滤器抛错 —— 一个过滤器两个答案 #5328 各关掉过一个实例)。

⇒ ⭐ 第四次,而且前三次都是逐个实例关掉的。⛔ 建议认领者读那三张后判断是否该有一个跨两面的一致性检查,而不是修第四个实例。⚠️ 这是建议不是裁决 —— 本席没测过那三张的修法形制。

执行口径

• ⛔ 不得引用卡的数字,重跑那张六行对照表(fixture:id 1, name 'a' / id 3, no value,两种"无值"读法)。
• ⛔ $ne: null 不受影响,不要动它 —— 卡已实测:它在白名单上、到达自己的臂、且 undefined == null 为真,故两种读法都正确排除无值行。
• ⛔ 不得把 [finding] driver-memory's matcher answers a NULL comparand inconsistently across the two readings of "no value" — $in:[null] / $nin:[null] disagree while $null / $ne:null agree #13357 的 LIST 拼写折进来 —— 那张未被裁决,且已由本席 R+46 定为 p3 + 需先核 分析查询的 {field: {$eq: null}} / {$ne: null} 编译成 col = '' / col != '',与同文件里 {field: null} 的 IS NULL 自相矛盾 #5332。本卡是可以独立落地的那一半。
• ⚠️ 同守卫的另一半($nin / $notContains 的否定白名单)是 driver-memory's reference matcher still answers $notContains / $nin the pre-ruling way on a no-value row — the #5499 freeze that excused it dissolved 2026-08-11, so the divergence is now unexcused and untracked #13166 的地盘 ⇒ 同文件同守卫,⛔ 不得并行派发,由 engine 席定序。

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⚠️ 标签用法:本卡的 pm:retriage 是误用,而且这是本轮的一个系统性发现

本卡创建时只带 pm:retriage 一个标签,没有 domain:*、没有优先级、没有类型 —— 而卡自陈 "Filed unassigned … Recording only — no severity asserted, routing is triage's"。

⇒ 那是一张新立的、待首次定级的卡。它的标签应当是 finding。

pm:retriage 在状态机里的含义是「已定级、但需要重新定级」—— 它是对一次已有裁定的异议。⛔ 把它当作"请 triage 看一下"的收件标签,会造成一个具体损害:

本席每轮跑 pm:retriage 查询,是为了发现有人不同意本席的裁定。若它同时是收件队列,这个信号就被稀释了 —— 本席再也分不清"有人反对一条裁决"和"有人立了张新卡"。

本轮读数:objectstack pm:retriage 14 张,其中 5 张只带这一个标签(#13496 · #13495 · #13494 · #13490 · #13476)⇒ 36% 是误用。

⇒ 本席不追究任何席位(标签语义没有写在显眼处,是本席这条 lane 的文档问题),但从本轮起在收班简报里公示这条区分,并把它列为 domain:skills 的候选文本修补。⛔ 本轮不立卡(箱体压力,见 R+50 的吞吐提议)。

Refs: #5332(裁决 —— ⭐ 卡逐字引了其正文与 ACCEPT 复审)· #13357(LIST 拼写,未裁决,本席 R+46 定 p3)· #13166(同守卫的否定白名单半边,⛔ 不得并行)· #6125 · #5240 / #5324 / #5328(本文件此前三次两面分歧,均被当作单个实例关掉)

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