hkjiang26 opened a new issue, #2507:
URL: https://github.com/apache/age/issues/2507
**Bug description**
Writing a Cypher `MATCH` pattern whose property-map value is a correlated
`EXISTS { }` subquery — the subquery projects an aggregate through `WITH` and
references the outer pattern variable — crashes the PostgreSQL backend with a
segmentation fault. The backend process is terminated (`signal 11: Segmentation
fault`) and the connection is dropped.
**Access method**
- Command line via `psql`, inside the official Docker container
`apache/age:1.8.0`
**Data setup**
Only a single vertex is required — no labels, properties, or edges:
```pgsql
CREATE EXTENSION IF NOT EXISTS age;
LOAD 'age';
SET search_path = ag_catalog, "$user", public;
SELECT create_graph('graph_test');
SELECT * FROM cypher('graph_test', $$ CREATE (n) $$) AS (c agtype);
```
**Configuration**
- None beyond the stock AGE extension. No additional modules (no PostGIS,
etc.), default `search_path` handling as shown above.
**Command that triggers the crash**
```pgsql
SELECT * FROM cypher('graph_test', $$ MATCH (x {n0: EXISTS { WITH sum(0) AS
n1, x RETURN 0 }}) RETURN 0 $$) AS (c agtype);
```
```
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
connection to server was lost
```
The server log shows the backend being killed:
```
LOG: client backend (PID NNN) was terminated by signal 11: Segmentation
fault
LOG: terminating any other active server processes
LOG: all server processes terminated; reinitializing
```
**Expected behavior**
The query is valid Cypher: an `EXISTS` subquery that always returns one row
is used as the value of a pattern property map. It should either match nodes
and return normally, or raise a normal Cypher error — it must not crash the
backend process. The same correlated subquery placed in a `WHERE` clause
instead of a property map executes correctly (returns `0`), so the crash is
specific to the property-map context.
**Removing any one of the following makes the crash disappear:**
- The subquery referencing the outer variable `x` (correlation)
- An aggregate (e.g. `sum`) projected in the subquery's `WITH` clause
- The `EXISTS` subquery being used as a pattern property-map value (same
subquery in `WHERE` does not crash)
**Environment**
- Version: 1.8.0 (official `apache/age:1.8.0` Docker image)
- PostgreSQL: 18.1 (Debian 18.1-1.pgdg13+2), x86_64
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