Add some minimal exercising of functional-index feature to regression

tests.

src/test/regress/expected/create_index.out

@@ -68,3 +68,16 @@ CREATE INDEX hash_name_index ON hash_name_heap USING hash (random name_ops);
 CREATE INDEX hash_txt_index ON hash_txt_heap USING hash (random text_ops);
 CREATE INDEX hash_f8_index ON hash_f8_heap USING hash (random float8_ops);
 -- CREATE INDEX hash_ovfl_index ON hash_ovfl_heap USING hash (x int4_ops);
+--
+-- Test functional index
+--
+CREATE TABLE func_index_heap (f1 text, f2 text);
+CREATE UNIQUE INDEX func_index_index on func_index_heap (textcat(f1,f2));
+INSERT INTO func_index_heap VALUES('ABC','DEF');
+INSERT INTO func_index_heap VALUES('AB','CDEFG');
+INSERT INTO func_index_heap VALUES('QWE','RTY');
+-- this should fail because of unique index:
+INSERT INTO func_index_heap VALUES('ABCD', 'EF');
+ERROR:  Cannot insert a duplicate key into unique index func_index_index
+-- but this shouldn't:
+INSERT INTO func_index_heap VALUES('QWERTY');

src/test/regress/expected/sanity_check.out

@@ -15,6 +15,7 @@ SELECT relname, relhasindex
  bt_name_heap        | t
  bt_txt_heap         | t
  fast_emp4000        | t
+ func_index_heap     | t
  hash_f8_heap        | t
  hash_i4_heap        | t
  hash_name_heap      | t
@@ -58,5 +59,5 @@ SELECT relname, relhasindex
  shighway            | t
  tenk1               | t
  tenk2               | t
-(48 rows)
+(49 rows)
 

src/test/regress/output/misc.source

@@ -599,6 +599,7 @@ SELECT user_relns() AS user_relns
  fast_emp4000
  float4_tbl
  float8_tbl
+ func_index_heap
  hash_f8_heap
  hash_i4_heap
  hash_name_heap
@@ -653,7 +654,7 @@ SELECT user_relns() AS user_relns
  toyemp
  varchar_tbl
  xacttest
-(90 rows)
+(91 rows)
 
 --SELECT name(equipment(hobby_construct(text 'skywalking', text 'mer'))) AS equip_name;
 SELECT hobbies_by_name('basketball');

src/test/regress/sql/create_index.sql

@@ -90,3 +90,17 @@ CREATE INDEX hash_f8_index ON hash_f8_heap USING hash (random float8_ops);
 
 -- CREATE INDEX hash_ovfl_index ON hash_ovfl_heap USING hash (x int4_ops);
 
+
+--
+-- Test functional index
+--
+CREATE TABLE func_index_heap (f1 text, f2 text);
+CREATE UNIQUE INDEX func_index_index on func_index_heap (textcat(f1,f2));
+
+INSERT INTO func_index_heap VALUES('ABC','DEF');
+INSERT INTO func_index_heap VALUES('AB','CDEFG');
+INSERT INTO func_index_heap VALUES('QWE','RTY');
+-- this should fail because of unique index:
+INSERT INTO func_index_heap VALUES('ABCD', 'EF');
+-- but this shouldn't:
+INSERT INTO func_index_heap VALUES('QWERTY');