handle empty arrays

PostgREST · Nov 26, 2023 · c75c14e · c75c14e
1 parent 12b10e1
commit c75c14e
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Showing 3 changed files with 58 additions and 26 deletions.
diff --git a/src/plmustache.c b/src/plmustache.c
@@ -190,6 +190,7 @@ Datum plmustache_handler(PG_FUNCTION_ARGS)
 			NullableDatum arg = fcinfo->args[i];
 			Oid arg_type = call_info.argtypes[i];
 			Oid array_elem_type = get_element_type(arg_type);
+			bool arg_is_array = array_elem_type != InvalidOid;
 
 			if(arg.isnull){
 				params[i].prm_value = NULL;
@@ -203,22 +204,22 @@ Datum plmustache_handler(PG_FUNCTION_ARGS)
 				else
 					params[i].enters_section = true;
 
-				params[i].is_array = array_elem_type != InvalidOid;
-
-				if(params[i].is_array){
-					int j = 0;
-					Datum value;
-					bool isnull;
+				if(arg_is_array){
+				  params[i].is_array = true;
 					ArrayType *array = DatumGetArrayTypeP(arg.value);
 					ArrayIterator array_iterator = array_create_iterator(array, 0, NULL);
-					int num = ArrayGetNItems(ARR_NDIM(array), ARR_DIMS(array));
-					params[i].prm_arr_length = num;
-					params[i].prm_arr = palloc0(sizeof(char*) * num);
-
-					while (array_iterate(array_iterator, &value, &isnull)) {
-						params[i].prm_arr[j] = isnull? NULL : datum_to_cstring(value, array_elem_type);
-						j++;
-					}
+					int arr_length = ArrayGetNItems(ARR_NDIM(array), ARR_DIMS(array));
+					if(arr_length > 0){
+						Datum value; bool isnull; int j = 0;
+						params[i].prm_arr_length = arr_length;
+						params[i].prm_arr = palloc0(sizeof(char*) * arr_length);
+
+						while (array_iterate(array_iterator, &value, &isnull)) {
+							params[i].prm_arr[j] = isnull? NULL : datum_to_cstring(value, array_elem_type);
+							j++;
+						}
+          } else
+						params[i].enters_section = false;
 				}
 
 			}

diff --git a/test/expected/sections.out b/test/expected/sections.out
@@ -82,46 +82,66 @@ select foo_null_test(true);
 (1 row)
 
 create or replace function foo_array(arr text[]) returns text as $$
-foo is {{#arr}}{{.}}, {{/arr}}
+arr is {{#arr}}{{.}}, {{/arr}}
 $$ language plmustache;
 \echo
 
 select foo_array(ARRAY['one', 'two', 'three']);
         foo_array         
 --------------------------
- foo is one, two, three, 
+ arr is one, two, three, 
 (1 row)
 
 create or replace function foo_array(arr int[]) returns text as $$
-foo is {{#arr}}{{.}}, {{/arr}}
+arr is {{#arr}}{{.}}, {{/arr}}
 $$ language plmustache;
 \echo
 
 select foo_array(ARRAY[1, 2, 3]::int[]);
     foo_array     
 ------------------
- foo is 1, 2, 3, 
+ arr is 1, 2, 3, 
+(1 row)
+
+-- empty array is handled properly
+select foo_array(ARRAY[]::int[]);
+ foo_array 
+-----------
+ arr is 
 (1 row)
 
 create or replace function mixed_var_array(var int, arr int[]) returns text as $$
-bar is {{var}}, foo is {{#arr}}{{.}}, {{/arr}}
+var is {{var}}, arr is {{#arr}}{{.}}, {{/arr}}
 $$ language plmustache;
 \echo
 
 select mixed_var_array(4, ARRAY[1, 2, 3]::int[]);
       mixed_var_array       
 ----------------------------
- bar is 4, foo is 1, 2, 3, 
+ var is 4, arr is 1, 2, 3, 
 (1 row)
 
 create or replace function mixed_array_var(arr int[], var int) returns text as $$
-foo is {{#arr}}{{.}}, {{/arr}} bar is {{var}}
+arr is {{#arr}}{{.}}, {{/arr}} var is {{var}}
 $$ language plmustache;
 \echo
 
 select mixed_array_var(ARRAY[1, 2, 3]::int[], 4);
       mixed_array_var      
 ---------------------------
- foo is 1, 2, 3,  bar is 4
+ arr is 1, 2, 3,  var is 4
+(1 row)
+
+create or replace function mixed_array_var_array(arr1 int[], var text, arr2 int[]) returns text as $$
+arr1 is {{#arr1}}{{.}}, {{/arr1}} var is {{var}}
+arr2 is {{#arr2}}{{.}}, {{/arr2}} var is {{var}}
+$$ language plmustache;
+\echo
+
+select mixed_array_var_array(ARRAY[1, 2, 3], 'something', ARRAY[4, 5, 6]);
+       mixed_array_var_array        
+------------------------------------
+ arr1 is 1, 2, 3,  var is something+
+ arr2 is 4, 5, 6,  var is something
 (1 row)
 
diff --git a/test/sql/sections.sql b/test/sql/sections.sql
@@ -45,29 +45,40 @@ select foo_null_test(null);
 select foo_null_test(true);
 
 create or replace function foo_array(arr text[]) returns text as $$
-foo is {{#arr}}{{.}}, {{/arr}}
+arr is {{#arr}}{{.}}, {{/arr}}
 $$ language plmustache;
 \echo
 
 select foo_array(ARRAY['one', 'two', 'three']);
 
 create or replace function foo_array(arr int[]) returns text as $$
-foo is {{#arr}}{{.}}, {{/arr}}
+arr is {{#arr}}{{.}}, {{/arr}}
 $$ language plmustache;
 \echo
 
 select foo_array(ARRAY[1, 2, 3]::int[]);
 
+-- empty array is handled properly
+select foo_array(ARRAY[]::int[]);
+
 create or replace function mixed_var_array(var int, arr int[]) returns text as $$
-bar is {{var}}, foo is {{#arr}}{{.}}, {{/arr}}
+var is {{var}}, arr is {{#arr}}{{.}}, {{/arr}}
 $$ language plmustache;
 \echo
 
 select mixed_var_array(4, ARRAY[1, 2, 3]::int[]);
 
 create or replace function mixed_array_var(arr int[], var int) returns text as $$
-foo is {{#arr}}{{.}}, {{/arr}} bar is {{var}}
+arr is {{#arr}}{{.}}, {{/arr}} var is {{var}}
 $$ language plmustache;
 \echo
 
 select mixed_array_var(ARRAY[1, 2, 3]::int[], 4);
+
+create or replace function mixed_array_var_array(arr1 int[], var text, arr2 int[]) returns text as $$
+arr1 is {{#arr1}}{{.}}, {{/arr1}} var is {{var}}
+arr2 is {{#arr2}}{{.}}, {{/arr2}} var is {{var}}
+$$ language plmustache;
+\echo
+
+select mixed_array_var_array(ARRAY[1, 2, 3], 'something', ARRAY[4, 5, 6]);