From 12f1c409daf2cdbd7d0323f0d61723819532b362 Mon Sep 17 00:00:00 2001
From: Hugo Herbelin
Date: Mon, 1 May 2017 16:56:25 +0200
Subject: Really fixing #2602 which was wrongly working because of #5487 hiding
 the cause.

The cause was a missing evar/evar clause in ltac pattern-matching
function (constr_matching.ml).
---
 pretyping/constr_matching.ml |  3 +++
 test-suite/success/ltac.v    | 13 +++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/pretyping/constr_matching.ml b/pretyping/constr_matching.ml
index 3c47cfdc4b..afdf601c21 100644
--- a/pretyping/constr_matching.ml
+++ b/pretyping/constr_matching.ml
@@ -347,6 +347,9 @@ let matches_core env sigma convert allow_partial_app allow_bound_rels
 
       |	PFix c1, Fix _ when eq_constr (mkFix c1) cT -> subst
       |	PCoFix c1, CoFix _ when eq_constr (mkCoFix c1) cT -> subst
+      | PEvar (c1,args1), Evar (c2,args2) when c1 = c2 ->
+         Array.fold_left2 (sorec ctx env) subst args1 args2
+
       | _ -> raise PatternMatchingFailure
 
   in
diff --git a/test-suite/success/ltac.v b/test-suite/success/ltac.v
index ce90990594..d7ec092d76 100644
--- a/test-suite/success/ltac.v
+++ b/test-suite/success/ltac.v
@@ -317,3 +317,16 @@ let T := constr:(fun a b : nat => a) in
   end.
 exact (eq_refl n).
 Qed.
+
+(* A variant of #2602 which was wrongly succeeding because "a", bound to
+   "?m", was then internally turned into a "_" in the second matching *)
+
+Goal exists m, S m > 0.
+eexists.
+Fail match goal with
+ | |- context [ S ?a ] =>
+     match goal with
+       | |- S a > a => idtac
+     end
+end.
+Abort.
-- 
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