Add a test for #34626

tests/queries/0_stateless/02808_aliases_inside_case.reference

@@ -0,0 +1,2 @@
+1	1
+2	0.5

tests/queries/0_stateless/02808_aliases_inside_case.sql

@@ -0,0 +1,10 @@
+# We support specifying aliases in any place in the query, including CASE expression:
+
+with arrayJoin([1,2]) as arg
+select arg,
+       (case
+           when arg = 1
+           then 1 as one
+           when arg = 2
+           then one / 2
+       end) as imposible;