fix(cypher): label-filtered edge traversal silently truncates at 10 results#412
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fix(cypher): label-filtered edge traversal silently truncates at 10 results#412isc-tdyar wants to merge 1 commit into
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…esults MATCH (c:Class)-[:DEFINES_METHOD]->(m:Method) returned at most 10 results for any class, regardless of how many methods it actually has. Root cause: bind_cap was set to scan_count (the number of nodes matched in the initial pattern — typically 1 when querying a single class by name). max_new = bind_cap * 10 = 10, so the edge expansion loop exited after collecting 10 results. No error, no warning, no truncation indicator. This is language-agnostic: any class with more than 10 methods in any language was silently truncated. The fix is two characters: bind_cap = scan_count > max_rows ? scan_count : max_rows Regression test: a Python class with 15 methods must return all 15 via MATCH (c:Class)-[:DEFINES_METHOD]->(m:Method) with label filtering.
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MATCH with label filters silently returns at most 10 results regardless of actual edge count
Discovered while using codebase-memory-mcp on a production codebase. A class with 37 methods returned only 10 via
MATCH (c:Class)-[:DEFINES_METHOD]->(m:Method). No error, no warning, no truncation indicator — the query appeared to succeed. Querying without label filters (MATCH (c)-[:DEFINES_METHOD]->(m)) returned all 37.Root cause
In
execute_single(),bind_capis set toscan_count— the number of nodes returned by the initial pattern scan. When matching a single class by name,scan_count = 1. The edge expansion loop then runs withmax_new = bind_cap * CYP_GROWTH_10 = 10, and exits after collecting 10 edges.This affects any label-filtered edge traversal where the initial pattern matches few nodes but each node has many edges. A single class with >10 methods, a single module with >10 imports, etc. Language-agnostic.
Regression test
A Python class with 15 methods indexed in full mode must return all 15 via
MATCH (c:Class)-[:DEFINES_METHOD]->(m:Method) WHERE c.name = 'BigClass'. Added totests/test_incremental.c.Relation to existing issues
This is a distinct variant of the "silent incomplete index" pattern tracked in #391. The difference: the graph is correctly built (all 37 edges exist in SQLite), but the Cypher query engine silently caps traversal at 10.
cbm_store_count_edges()returns the correct total; the truncation only appears when querying with label-typed patterns.Happy to add more detail to the test if useful.