From 2f13de7a48ab956dde06cc6a8ad5a9f93fd84c04 Mon Sep 17 00:00:00 2001
From: Jules Aguillon <jules@j3s.fr>
Date: Fri, 13 Dec 2024 10:40:22 +0100
Subject: [PATCH] test: Repro 'dune fmt' crash in presence of Nix result

A 'ocamlformat' executable is added to the test to avoid depending on
OCamlformat.

Signed-off-by: Jules Aguillon <jules@j3s.fr>
---
 .../read-only-symlink-target.t/.ocamlformat      |  0
 .../test-cases/read-only-symlink-target.t/dune   |  2 ++
 .../read-only-symlink-target.t/dune-project      |  1 +
 .../read-only-symlink-target.t/ocamlformat.ml    |  2 ++
 .../test-cases/read-only-symlink-target.t/run.t  | 16 ++++++++++++++++
 5 files changed, 21 insertions(+)
 create mode 100644 test/blackbox-tests/test-cases/read-only-symlink-target.t/.ocamlformat
 create mode 100644 test/blackbox-tests/test-cases/read-only-symlink-target.t/dune
 create mode 100644 test/blackbox-tests/test-cases/read-only-symlink-target.t/dune-project
 create mode 100644 test/blackbox-tests/test-cases/read-only-symlink-target.t/ocamlformat.ml
 create mode 100644 test/blackbox-tests/test-cases/read-only-symlink-target.t/run.t

diff --git a/test/blackbox-tests/test-cases/read-only-symlink-target.t/.ocamlformat b/test/blackbox-tests/test-cases/read-only-symlink-target.t/.ocamlformat
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/test/blackbox-tests/test-cases/read-only-symlink-target.t/dune b/test/blackbox-tests/test-cases/read-only-symlink-target.t/dune
new file mode 100644
index 00000000000..75e3ba2509e
--- /dev/null
+++ b/test/blackbox-tests/test-cases/read-only-symlink-target.t/dune
@@ -0,0 +1,2 @@
+(executable
+ (name ocamlformat))
diff --git a/test/blackbox-tests/test-cases/read-only-symlink-target.t/dune-project b/test/blackbox-tests/test-cases/read-only-symlink-target.t/dune-project
new file mode 100644
index 00000000000..c2e46604eed
--- /dev/null
+++ b/test/blackbox-tests/test-cases/read-only-symlink-target.t/dune-project
@@ -0,0 +1 @@
+(lang dune 2.8)
diff --git a/test/blackbox-tests/test-cases/read-only-symlink-target.t/ocamlformat.ml b/test/blackbox-tests/test-cases/read-only-symlink-target.t/ocamlformat.ml
new file mode 100644
index 00000000000..4099c65085d
--- /dev/null
+++ b/test/blackbox-tests/test-cases/read-only-symlink-target.t/ocamlformat.ml
@@ -0,0 +1,2 @@
+(* Avoid adding dependencies to this cram test *)
+let () = print_endline "(* formatted *)"
diff --git a/test/blackbox-tests/test-cases/read-only-symlink-target.t/run.t b/test/blackbox-tests/test-cases/read-only-symlink-target.t/run.t
new file mode 100644
index 00000000000..43760753360
--- /dev/null
+++ b/test/blackbox-tests/test-cases/read-only-symlink-target.t/run.t
@@ -0,0 +1,16 @@
+Nix can leave a symlink to a store path in the tree, often called 'result'.
+'dune fmt' crashes because of that.
+
+  $ RESULT=`mktemp -d`
+  $ echo "let x  = 2" > "$RESULT/foo.ml"
+  $ chmod -R a-w "$RESULT"
+  $ ln -s "$RESULT" result
+
+This command should succeed:
+
+  $ dune fmt 2>/dev/null
+  [1]
+
+Allow Dune to remove temporary files (calling Dune crashes without this):
+
+  $ chmod -R u+w "$RESULT"