2 files changed, 42 insertions, 0 deletions
diff --git a/src/test/regress/expected/enum.out b/src/test/regress/expected/enum.out
index bf94af5ef6e..a14097297a1 100644
--- a/src/test/regress/expected/enum.out
+++ b/src/test/regress/expected/enum.out
@@ -95,6 +95,28 @@ ERROR:  invalid enum label "plutoplutoplutoplutoplutoplutoplutoplutoplutoplutopl
 DETAIL:  Labels must be 63 characters or less.
 ALTER TYPE planets ADD VALUE 'pluto' AFTER 'zeus';
 ERROR:  "zeus" is not an existing enum label
+-- if not exists tests
+--  existing value gives error
+-- We can't do this test because the error contains the
+-- offending Oid value, which is unpredictable.
+-- ALTER TYPE planets ADD VALUE 'mercury';
+-- unless IF NOT EXISTS is specified
+ALTER TYPE planets ADD VALUE IF NOT EXISTS 'mercury';
+-- should be neptune, not mercury
+SELECT enum_last(NULL::planets);
+ enum_last 
+-----------
+ neptune
+(1 row)
+
+ALTER TYPE planets ADD VALUE IF NOT EXISTS 'pluto';
+-- should be pluto, i.e. the new value
+SELECT enum_last(NULL::planets);
+ enum_last 
+-----------
+ pluto
+(1 row)
+
 --
 -- Test inserting so many values that we have to renumber
 --
diff --git a/src/test/regress/sql/enum.sql b/src/test/regress/sql/enum.sql
index 7ca62483096..db7bf44b408 100644
--- a/src/test/regress/sql/enum.sql
+++ b/src/test/regress/sql/enum.sql
@@ -54,6 +54,26 @@ ALTER TYPE planets ADD VALUE
 
 ALTER TYPE planets ADD VALUE 'pluto' AFTER 'zeus';
 
+-- if not exists tests
+
+--  existing value gives error
+
+-- We can't do this test because the error contains the
+-- offending Oid value, which is unpredictable.
+-- ALTER TYPE planets ADD VALUE 'mercury';
+
+-- unless IF NOT EXISTS is specified
+ALTER TYPE planets ADD VALUE IF NOT EXISTS 'mercury';
+
+-- should be neptune, not mercury
+SELECT enum_last(NULL::planets);
+
+ALTER TYPE planets ADD VALUE IF NOT EXISTS 'pluto';
+
+-- should be pluto, i.e. the new value
+SELECT enum_last(NULL::planets);
+
+
 --
 -- Test inserting so many values that we have to renumber
 --