Partial backtrack on wrong r14204: bug #2490 still open.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@14218 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 28 insertions, 0 deletions

diff --git a/test-suite/bugs/opened/shouldnotsucceed/2490.v b/test-suite/bugs/opened/shouldnotsucceed/2490.v
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+++ b/test-suite/bugs/opened/shouldnotsucceed/2490.v
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+Class Rel A := rel : A -> Prop.
+Class Rel2 A := rel2 : A -> Prop.
+Class Property A (o : A -> Prop) := rel_property : True.
+
+Class Op A := op : A -> A.
+Instance my_op {A} {r : Rel A} {p : Property A r} : Op A := fun x => x.
+
+Section test.
+Context A (r2 : Rel2 A) (p2 : Property A r2).
+
+(* 8.3 yields an error: "Could not find an instance for "Op A" in environment".
+  Trunk, on the other hand, uses [r2] as an instance of [Rel] and hence finds
+the previously defined instance of [Op]. Trunk's behavior is incorrect. *)
+Lemma test (x : A) : op x = op x.
+Admitted.
+
+(* If we don't refer to the canonical name, Coq will actually complain, as it
+should. *)
+Lemma test (x : A) : my_op x = my_op x.
+
+End test.
+
+(* Now we make an instance of [Op] without dependent condition. *)
+Instance my_op_nondep {A} {r : Rel A} : Op A := fun x => x.
+
+Section test2.
+Context A (r2 : Rel2 A).
+