Fixes #12348: long-standing de Bruijn indices bug in imitation (solve_simple_eqn).

The bug was that an assumption could be interpreted as a local
definition and wrongly expanded.

It triggered rarely because it involved mixing let-ins and
local assumptions + imitation under binders.

1 files changed, 11 insertions, 0 deletions

diff --git a/test-suite/bugs/closed/bug_12348.v b/test-suite/bugs/closed/bug_12348.v
new file mode 100644
index 0000000000..93ba6f17e0
--- /dev/null
+++ b/test-suite/bugs/closed/bug_12348.v
@@ -0,0 +1,11 @@
+(* Was raising an anomaly before 8.13 *)
+Check let 'tt := tt in
+      let X := nat in
+      let b : bool := _ in
+      (fun n : nat => 0 : X) : _.
+
+(* Was raising an ill-typed instance error before 8.13 *)
+Check let 'tt := tt in
+      let X := nat in
+      let b : bool := true in
+      (fun n : nat => 0 : X) : _.