From b29c19ca657c41208bf76706773c7cbc59ef38f8 Mon Sep 17 00:00:00 2001
From: Jan Midtgaard <mail@janmidtgaard.dk>
Date: Fri, 28 Jun 2024 11:55:41 +0200
Subject: [PATCH 1/2] Remove {,get_}instances as it is causing a memory leak
 #287

---
 src/core/QCheck2.ml  | 8 +-------
 src/core/QCheck2.mli | 4 ----
 2 files changed, 1 insertion(+), 11 deletions(-)

diff --git a/src/core/QCheck2.ml b/src/core/QCheck2.ml
index a0cc4e7b..1bf96d2b 100644
--- a/src/core/QCheck2.ml
+++ b/src/core/QCheck2.ml
@@ -1354,9 +1354,6 @@ module TestResult = struct
     collect_tbl: (string, int) Hashtbl.t lazy_t;
     stats_tbl: ('a stat * (int, int) Hashtbl.t) list;
     mutable warnings: string list;
-    mutable instances: 'a list;
-    (** List of instances used for this test, in no particular order.
-        @since 0.9 *)
   }
 
   let get_state {state; _} = state
@@ -1391,8 +1388,6 @@ module TestResult = struct
 
   let warnings = get_warnings
 
-  let get_instances r = r.instances
-
   let is_success r = match r.state with
     | Success -> true
     | Failed _ | Error _ | Failed_other _ -> false
@@ -1763,7 +1758,6 @@ module Test = struct
   and check_state_input state input_tree =
     let Tree.Tree (input, _) = input_tree in
     state.handler state.test.name state.test (Collecting input);
-    state.res.R.instances <- input :: state.res.R.instances;
     collect state input;
     update_stats state input;
     let res =
@@ -1835,7 +1829,7 @@ module Test = struct
       res = {R.
               state=R.Success; count=0; count_gen=0;
               collect_tbl=lazy (Hashtbl.create 10);
-              instances=[]; warnings=[];
+              warnings=[];
               stats_tbl= List.map (fun stat -> stat, Hashtbl.create 10) cell.stats;
             };
     } in
diff --git a/src/core/QCheck2.mli b/src/core/QCheck2.mli
index 75f68ce8..ceed40e5 100644
--- a/src/core/QCheck2.mli
+++ b/src/core/QCheck2.mli
@@ -1610,10 +1610,6 @@ module TestResult : sig
   (** [get_warnings t] returns the list of warnings emitted during the test.
       @since 0.18 *)
 
-  val get_instances : 'a t -> 'a list
-  (** [get_instances t] returns the generated instances, with no guarantee on the order.
-      @since 0.18 *)
-
   val is_success : _ t -> bool
   (** Returns true iff the state is [Success]
       @since 0.9 *)

From 55b3f859878b94c08a4a96ff84c1c662ede728cf Mon Sep 17 00:00:00 2001
From: Jan Midtgaard <mail@janmidtgaard.dk>
Date: Fri, 28 Jun 2024 12:03:49 +0200
Subject: [PATCH 2/2] Add a CHANGELOG entry

---
 CHANGELOG.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index cbb35752..eb767a0d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,8 @@
 
 ## NEXT RELEASE
 
-- ...
+- Remove `QCheck2.TestResult.get_instances` as retaining previous test inputs
+  cause memory leaks
 
 ## 0.21.3