From defac2fdb15b4f23aebe3df3638cf98dad23a747 Mon Sep 17 00:00:00 2001
From: Marcel van Lohuizen <mpvl@gmail.com>
Date: Tue, 12 May 2026 11:05:11 +0200
Subject: [PATCH] internal/core/adt: add reproducer for unity failure
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Lock in the correct behavior of a comprehension-over-resources
shape originally surfaced by unity. The upcoming comprehension
rework would otherwise regress this case; landing the test below
the rework lets the follow-up fix show its diff cleanly.

Signed-off-by: Marcel van Lohuizen <mpvl@gmail.com>
Change-Id: Ic09a34161212ac5e79f3dcf26a5134b3bc305cb0
Reviewed-on: https://cue.gerrithub.io/c/cue-lang/cue/+/1237116
TryBot-Result: CUEcueckoo <cueckoo@cuelang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Unity-Result: CUE porcuepine <cue.porcuepine@gmail.com>
---
 .../comprehensions/deferfieldsetknown.txtar   | 43 +++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 cue/testdata/comprehensions/deferfieldsetknown.txtar

diff --git a/cue/testdata/comprehensions/deferfieldsetknown.txtar b/cue/testdata/comprehensions/deferfieldsetknown.txtar
new file mode 100644
index 000000000..d5d5b1d75
--- /dev/null
+++ b/cue/testdata/comprehensions/deferfieldsetknown.txtar
@@ -0,0 +1,43 @@
+-- in.cue --
+package x
+
+#PDB: {y: int}
+
+result: resources: {
+    if true {
+        x: #PDB & {y: 1}
+    }
+}
+
+out: ({
+    cfg: resources: _
+    out: {for n, _ in cfg.resources {(n): "x"}}
+} & {cfg: result}).out @test(eq, {x: "x"})
+-- out/compile --
+--- in.cue
+{
+  #PDB: {
+    y: int
+  }
+  result: {
+    resources: {
+      if true {
+        x: (〈3;#PDB〉 & {
+          y: 1
+        })
+      }
+    }
+  }
+  out: ({
+    cfg: {
+      resources: _
+    }
+    out: {
+      for n, _ in 〈1;cfg〉.resources {
+        〈1;n〉: "x"
+      }
+    }
+  } & {
+    cfg: 〈1;result〉
+  }).out
+}
-- 
2.51.2