Recovering 8.2 behavior of "simple (e)apply" (and hence of "(e)auto").

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@12927 85f007b7-540e-0410-9357-904b9bb8a0f7

2 files changed, 27 insertions, 1 deletions

diff --git a/pretyping/unification.ml b/pretyping/unification.ml
index 648dcee0c8..35543ce24a 100644
--- a/pretyping/unification.ml
+++ b/pretyping/unification.ml
@@ -187,7 +187,7 @@ let default_no_delta_unify_flags = {
   use_metas_eagerly = true;
   modulo_delta = empty_transparent_state;
   resolve_evars = false;
-  use_evars_pattern_unification = true;
+  use_evars_pattern_unification = false;
 }
 
 let use_evars_pattern_unification flags =
diff --git a/test-suite/success/apply.v b/test-suite/success/apply.v
index 10182bdc8c..a6f9fa238d 100644
--- a/test-suite/success/apply.v
+++ b/test-suite/success/apply.v
@@ -358,6 +358,32 @@ intro x;
 apply x.
 Qed.
 
+(* The following worked in 8.2 but was not accepted from r12229 to
+   r12926 because "simple apply" started to use pattern unification of
+   evars. Evars pattern unification for simple (e)apply was disabled
+   in 12927 but "simple eapply" below worked from 12898 to 12926
+   because pattern-unification also started supporting abstraction
+   over Metas. However it did not find the "simple" solution and hence
+   the subsequent "assumption" failed. *)
+
+Goal exists f:nat->nat, forall x y, x = y -> f x = f y.
+intros; eexists; intros.
+simple eapply (@f_equal nat).
+assumption.
+Existential 1 := fun x => x.
+Qed.
+
+(* The following worked in 8.2 but was not accepted from r12229 to
+   r12897 for the same reason because eauto uses "simple apply". It
+   worked from 12898 to 12926 because eauto uses eassumption and not
+   assumption. *)
+
+Goal exists f:nat->nat, forall x y, x = y -> f x = f y.
+intros; eexists; intros.
+eauto.
+Existential 1 := fun x => x.
+Qed.
+
 (* The following was accepted before r12612 but is still not accepted in r12658
 
 Goal forall x : { x:nat | x = 0}, proj1_sig x = 0.