Fix POST, PATCH, DELETE with ?select= and empty body or return=minimal (#1471)

* add tests for POST, PATCH, DELETE when using ?select= with empty bodies or ret=min

* fix select with empty bodies and ret=min

* improved tests for default cases, fixed computed overloaded columns on empty-body?select= PATCH

src/PostgREST/Statements.hs

@@ -55,7 +55,7 @@ createWriteStatement selectQuery mutateQuery wantSingle isInsert asCsv rep pKeys
         {locF} AS header,
         {bodyF} AS body,
         {responseHeadersF pgVer} AS response_headers
-      FROM ({selectQuery}) _postgrest_t |]
+      FROM ({selectF}) _postgrest_t |]
 
   locF =
     if isInsert && rep `elem` [Full, HeadersOnly]
@@ -72,6 +72,11 @@ createWriteStatement selectQuery mutateQuery wantSingle isInsert asCsv rep pKeys
     | wantSingle = asJsonSingleF
     | otherwise = asJsonF
 
+  selectF
+    -- prevent using any of the column names in ?select= when no response is returned from the CTE
+    | rep `elem` [None, HeadersOnly] = "SELECT * FROM " <> sourceCTEName
+    | otherwise                      = selectQuery
+
   decodeStandard :: HD.Result ResultsWithCount
   decodeStandard =
    fromMaybe (Nothing, 0, [], mempty, Right []) <$> HD.rowMaybe standardRow