From d2a0e526dad259f71fc7f741129aba8e476c8f7a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Reynir=20Bj=C3=B6rnsson?= <reynir@reynir.dk>
Date: Thu, 19 Dec 2024 15:05:48 +0100
Subject: [PATCH] Remove an assert false, and silence warning 8

---
 src/git_kv.ml | 41 +++++++++++++++++++++--------------------
 1 file changed, 21 insertions(+), 20 deletions(-)

diff --git a/src/git_kv.ml b/src/git_kv.ml
index 14740d4..090d87d 100644
--- a/src/git_kv.ml
+++ b/src/git_kv.ml
@@ -472,26 +472,27 @@ module Make (Pclock : Mirage_clock.PCLOCK) = struct
            ~none:Ptime.epoch
            ~some:Fun.id (Ptime.of_float_s (Int64.to_float (now ()))))
     | None, Some head ->
-      Store.read_exn t.store head >|= function
-      | Commit c ->
-        let author = Git_commit.author c in
-        let secs, tz_offset = author.Git.User.date in
-        let secs =
-          Option.fold ~none:secs
-            ~some:(fun { Git.User.sign ; hours ; minutes } ->
-                let tz_off = Int64.(mul (add (mul (of_int hours) 60L) (of_int minutes)) 60L) in
-                match sign with
-                | `Plus -> Int64.(sub secs tz_off)
-                | `Minus -> Int64.(add secs tz_off))
-            tz_offset
-        in
-        let ts =
-          Option.fold
-            ~none:Ptime.epoch
-            ~some:Fun.id (Ptime.of_float_s (Int64.to_float secs))
-        in
-        Ok ts
-      | _ -> assert false
+      (* See https://github.com/ocaml/ocaml/issues/9301 why we have the
+         intermediate [r] value. *)
+      let+ r = Store.read_exn t.store head in
+      let[@warning "-8"] Commit c = r in
+      let author = Git_commit.author c in
+      let secs, tz_offset = author.Git.User.date in
+      let secs =
+        Option.fold ~none:secs
+          ~some:(fun { Git.User.sign ; hours ; minutes } ->
+              let tz_off = Int64.(mul (add (mul (of_int hours) 60L) (of_int minutes)) 60L) in
+              match sign with
+              | `Plus -> Int64.(sub secs tz_off)
+              | `Minus -> Int64.(add secs tz_off))
+          tz_offset
+      in
+      let ts =
+        Option.fold
+          ~none:Ptime.epoch
+          ~some:Fun.id (Ptime.of_float_s (Int64.to_float secs))
+      in
+      Ok ts
 
   let digest t key =
     let open Lwt.Infix in