The WHERE parser rejected coalesce() outright ('unexpected operator'),
blocking null-safe numeric filters over optional graph properties —
the exact audit-query shape from the report:
MATCH (f:Function) WHERE coalesce(f.transitive_loop_depth, 0) >= 2
RETURN-side coalesce already worked; only the WHERE leaf lacked it.
Implementation: the condition leaf gains a coalesce_default literal.
The operator/value tail of condition parsing is factored into a shared
parse_condition_op so both subjects (var[.prop] and
coalesce(var.prop, literal)) accept the full operator set (comparisons,
IS [NOT] NULL, IN). At eval time a missing/empty property value is
substituted with the default before the operator runs. Supported form
is coalesce(var.prop, literal) — matching openCypher's two-argument
null-substitution for this subset.
Reproduce-first: cypher_exec_where_coalesce_issue874 runs the
reporter's exact query — RED (rc=-1 parse error) on the old parser —
and pins both directions: a failing default excludes property-less
nodes, a passing default includes them.
Closes#874
Signed-off-by: Martin Vogel <martin.vogel.tech@gmail.com>
Martin Vogel
4382b97908