More spec tests

Author: alex-spies

x-pack/plugin/esql/qa/testFixtures/src/main/resources/lookup-join.csv-spec

@@ -146,7 +146,6 @@ emp_no:integer | language_code:integer | language_name:keyword
 
 multipleLookupsAndProjects
 required_capability: join_lookup_v12
-# TODO: this test, but with a lookup index that has multiple matches per row to show the first LOOKUP's effect, too.
 
 FROM employees
 | KEEP languages, emp_no
@@ -167,6 +166,44 @@ languages:integer | emp_no:integer | language_code:integer | language_name:keywo
 1                 | 10005          | 1                     | English
 ;
 
+multipleLookupsAndProjectsNonUnique
+required_capability: join_lookup_v12
+
+FROM employees
+| KEEP languages, emp_no
+| EVAL language_code = languages
+# this lookup contributes 0 fields in the end, but it contributes rows via multiple matches
+| LOOKUP JOIN languages_lookup_non_unique_key ON language_code
+| RENAME language_name AS foo
+| LOOKUP JOIN languages_lookup ON language_code
+| DROP foo, country, country.keyword
+| SORT emp_no
+| LIMIT 5
+;
+
+languages:integer | emp_no:integer | language_code:integer | language_name:keyword
+2                 | 10001          | 2                     | French
+2                 | 10001          | 2                     | French
+2                 | 10001          | 2                     | French
+5                 | 10002          | 5                     | null
+4                 | 10003          | 4                     | German
+;
+
+projectsWithShadowingAfterPushdown
+required_capability: join_lookup_v12
+
+FROM languages_lookup
+| WHERE language_code == 4
+# not shadowed - unless the rename would happen after the lookup
+| RENAME language_name AS original_language_name
+| LOOKUP JOIN languages_lookup_non_unique_key ON language_code
+| DROP country*
+;
+
+language_code:integer | original_language_name:keyword | language_name:keyword
+4                     | German                         | Quenya
+;
+
 ###########################################################################
 # multiple match behavior with languages_lookup_non_unique_key index
 ###########################################################################