Fix evar bugs in type classes:

- disallow uninstantiated hypotheses (typically local variables with no
assigned types) as solutions for typeclass instantiation.
- Fix resolve_typeclasses call in pretyping that was not propagating
found instances in the term.


git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@10772 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 5 insertions, 3 deletions

diff --git a/pretyping/pretyping.ml b/pretyping/pretyping.ml
index 83381710d..df1e45d86 100644
--- a/pretyping/pretyping.ml
+++ b/pretyping/pretyping.ml
@@ -687,9 +687,11 @@ module Pretyping_F (Coercion : Coercion.S) = struct
     let c = pretype_gen evdref env lvar kind c in
     let evd,_ = consider_remaining_unif_problems env !evdref in
       if fail_evar then 
-	(let evd = Typeclasses.resolve_typeclasses ~onlyargs:false ~all:false env (evars_of evd) evd in
-	   check_evars env Evd.empty evd c);
-      evd, c
+	let evd = Typeclasses.resolve_typeclasses ~onlyargs:false ~all:false env (evars_of evd) evd in
+	let c = Evarutil.nf_isevar evd c in
+	  check_evars env Evd.empty evd c;
+	  evd, c
+      else evd, c
 
   (** Entry points of the high-level type synthesis algorithm *)