Do Not Merge! Fix for Aliases and Lazy Materialization

[ilejn]

Changelog category (leave one):

• Bug Fix (user-visible misbehavior in an official stable release)

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):

Logical Error fixed if both Alias and original column are selected.

Documentation entry for user-facing changes

...

CI/CD Options

Exclude tests:

• Fast test
• Integration Tests
• Stateless tests
• Stateful tests
• Unit tests
• Performance tests
• Aarch64 tests
• All with ASAN
• All with TSAN
• All with MSAN
• All with UBSAN
• All with Coverage
• All Regression
• Disable CI Cache

Regression jobs to run:

• Fast suites (mostly <1h)
• Aggregate Functions (2h)
• Alter (1.5h)
• Benchmark (30m)
• CAS (content-addressed storage; Antalya only)
• ClickHouse Keeper (1h)
• Iceberg (2h)
• LDAP (1h)
• OAuth (5m)
• Parquet (1.5h)
• RBAC (1.5h)
• SSL Server (1h)
• S3 (2h)
• S3 Export (2h)
• Swarms (30m)
• Tiered Storage (2h)

[ilejn]

Repro

CREATE TABLE t_str (id UInt64, ts DateTime, s String, s_alias String ALIAS s)
ENGINE = MergeTree ORDER BY id;
INSERT INTO t_str SELECT number, toDateTime('2026-01-01 00:00:00') + number, toString(number) FROM numbers(100);
SELECT s, s_alias FROM t_str ORDER BY ts DESC LIMIT 10;

[github-actions]

Workflow [PR], commit [a2ea700]