Fix issue 1953 - PG Boolean used as AGTYPE object (apache#1959)

Fixed issue 1953 - Server crashes when executing -

 SELECT * FROM cypher('ag_graph_3'...)

This was due to the executor phase trying to use a PG Boolean as
an AGTYPE object for the indirection argument.

The fix was to use coerce_to_common_type on the input argument in
transform_A_Indirection.

Added regression tests.

regress/expected/expr.out

@@ -8426,8 +8426,56 @@ ERROR:  argument 1: key must not be null
 SELECT agtype_build_map('name', 'John', 'null'::agtype, 1);
 ERROR:  argument 3: key must not be null
 --
+-- Issue 1953 - crash when trying to use a boolean as an object
+--
+SELECT * FROM create_graph('issue_1953');
+NOTICE:  graph "issue_1953" has been created
+ create_graph 
+--------------
+
+(1 row)
+
+SELECT * FROM cypher('issue_1953', $$ RETURN delete_global_graphs('issue_1953')[{}][{}][{}][{}][{}] $$) AS (result agtype);
+ERROR:  A_indirection could not convert type boolean to agtype
+LINE 1: ...ypher('issue_1953', $$ RETURN delete_global_graphs('issue_19...
+                                                             ^
+SELECT * FROM cypher('issue_1953', $$ RETURN delete_global_graphs('issue_1953')[{}] $$) AS (result agtype);
+ERROR:  A_indirection could not convert type boolean to agtype
+LINE 1: ...ypher('issue_1953', $$ RETURN delete_global_graphs('issue_19...
+                                                             ^
+SELECT * FROM cypher('issue_1953', $$ RETURN delete_global_graphs('issue_1953')[0] $$) AS (result agtype);
+ERROR:  A_indirection could not convert type boolean to agtype
+LINE 1: ...ypher('issue_1953', $$ RETURN delete_global_graphs('issue_19...
+                                                             ^
+SELECT * FROM cypher('issue_1953', $$ RETURN delete_global_graphs('issue_1953')[0..1] $$) AS (result agtype);
+ERROR:  A_indirection could not convert type boolean to agtype
+LINE 1: ...ypher('issue_1953', $$ RETURN delete_global_graphs('issue_19...
+                                                             ^
+SELECT * FROM cypher('issue_1953', $$ RETURN is_valid_label_name('issue_1953')[{}] $$) AS (result agtype);
+ERROR:  A_indirection could not convert type boolean to agtype
+LINE 1: ...cypher('issue_1953', $$ RETURN is_valid_label_name('issue_19...
+                                                             ^
+SELECT * FROM cypher('issue_1953', $$ RETURN is_valid_label_name('issue_1953')[0] $$) AS (result agtype);
+ERROR:  A_indirection could not convert type boolean to agtype
+LINE 1: ...cypher('issue_1953', $$ RETURN is_valid_label_name('issue_19...
+                                                             ^
+SELECT * FROM cypher('issue_1953', $$ RETURN is_valid_label_name('issue_1953')[0..1] $$) AS (result agtype);
+ERROR:  A_indirection could not convert type boolean to agtype
+LINE 1: ...cypher('issue_1953', $$ RETURN is_valid_label_name('issue_19...
+                                                             ^
+--
 -- Cleanup
 --
+SELECT * FROM drop_graph('issue_1953', true);
+NOTICE:  drop cascades to 2 other objects
+DETAIL:  drop cascades to table issue_1953._ag_label_vertex
+drop cascades to table issue_1953._ag_label_edge
+NOTICE:  graph "issue_1953" has been dropped
+ drop_graph 
+------------
+
+(1 row)
+
 SELECT * FROM drop_graph('expanded_map', true);
 NOTICE:  drop cascades to 2 other objects
 DETAIL:  drop cascades to table expanded_map._ag_label_vertex

regress/sql/expr.sql

@@ -3431,9 +3431,23 @@ SELECT agtype_build_map('null'::agtype, 1);
 SELECT agtype_build_map(null, 1);
 SELECT agtype_build_map('name', 'John', 'null'::agtype, 1);
 
+--
+-- Issue 1953 - crash when trying to use a boolean as an object
+--
+SELECT * FROM create_graph('issue_1953');
+SELECT * FROM cypher('issue_1953', $$ RETURN delete_global_graphs('issue_1953')[{}][{}][{}][{}][{}] $$) AS (result agtype);
+SELECT * FROM cypher('issue_1953', $$ RETURN delete_global_graphs('issue_1953')[{}] $$) AS (result agtype);
+SELECT * FROM cypher('issue_1953', $$ RETURN delete_global_graphs('issue_1953')[0] $$) AS (result agtype);
+SELECT * FROM cypher('issue_1953', $$ RETURN delete_global_graphs('issue_1953')[0..1] $$) AS (result agtype);
+
+SELECT * FROM cypher('issue_1953', $$ RETURN is_valid_label_name('issue_1953')[{}] $$) AS (result agtype);
+SELECT * FROM cypher('issue_1953', $$ RETURN is_valid_label_name('issue_1953')[0] $$) AS (result agtype);
+SELECT * FROM cypher('issue_1953', $$ RETURN is_valid_label_name('issue_1953')[0..1] $$) AS (result agtype);
+
 --
 -- Cleanup
 --
+SELECT * FROM drop_graph('issue_1953', true);
 SELECT * FROM drop_graph('expanded_map', true);
 SELECT * FROM drop_graph('issue_1124', true);
 SELECT * FROM drop_graph('issue_1303', true);

src/backend/parser/cypher_expr.c

@@ -1318,6 +1318,7 @@ static Node *transform_column_ref_for_indirection(cypher_parsestate *cpstate,
 static Node *transform_A_Indirection(cypher_parsestate *cpstate,
                                      A_Indirection *a_ind)
 {
+    ParseState *pstate = &cpstate->pstate;
     int location;
     ListCell *lc = NULL;
     Node *ind_arg_expr = NULL;
@@ -1356,6 +1357,9 @@ static Node *transform_A_Indirection(cypher_parsestate *cpstate,
         ind_arg_expr = transform_cypher_expr_recurse(cpstate, a_ind->arg);
     }
 
+    ind_arg_expr = coerce_to_common_type(pstate, ind_arg_expr, AGTYPEOID,
+                                         "A_indirection");
+
     /* get the location of the expression */
     location = exprLocation(ind_arg_expr);