RockteMQ-AI commented on issue #11437:
URL: https://github.com/apache/rocketmq/issues/11437#issuecomment-6166898813
## ๐ค Bot Evaluation: โ
Bug Confirmed
**Category:** `type/bug`
**Severity:** Medium โ silent data loss in message filtering; consumers
receive messages that should have been filtered out.
### Verification
I verified the bug by inspecting the source code on `develop` branch:
1.
**`filter/src/main/java/org/apache/rocketmq/filter/parser/SelectorParser.java`**
โ The `JmsSelector()` start rule parses one `orExpression()` and returns
immediately. There is no `jj_consume_token(0)` or equivalent EOF check anywhere
in the file.
2.
**`filter/src/main/java/org/apache/rocketmq/filter/parser/SelectorParser.jj`**
(lines 200โ210) โ The grammar rule for `JmsSelector()` has no `<EOF>` token at
the end:
```
BooleanExpression JmsSelector() :
{ Expression left=null; }
{
( left = orExpression() )
{ return asBooleanExpression(left); }
}
```
3. **Impact confirmed:** `SelectorParser.parse("a = 3 b = 4")` returns `(a =
3)` โ the second clause is silently dropped. This affects both client-side
subscription (`MessageSelector.bySql(...)`) and broker-side filter compilation
(`SqlFilter.compile(...)` via `ConsumerFilterManager.build`).
### Root Cause
The JavaCC-generated parser consumes only as much input as matches the
grammar and never asserts that the entire input string was consumed. Any
trailing tokens after a valid expression are silently ignored.
### Suggested Fix
Add `<EOF>` to the grammar rule in `SelectorParser.jj`:
```
BooleanExpression JmsSelector() :
{ Expression left=null; }
{
( left = orExpression() ) <EOF>
{ return asBooleanExpression(left); }
}
```
Then regenerate `SelectorParser.java` from the grammar. This will cause the
parser to throw a `ParseException` when trailing tokens remain.
### Notes
- The issue description is thorough and well-reproduced. Thank you
@iloveeyjafjalla!
- The referenced PR #602 (2018) attempted a similar fix but was not merged.
- The author mentioned they will open a PR โ looking forward to it.
---
*Evaluated by [RockteMQ-AI](https://github.com/RockteMQ-AI) bot ยท Issue
evaluation workflow*
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