From b39ac541f52eefc1225961dcb781134d4c617e53 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Pit-Claudel?= <cpitcla@amazon.com>
Date: Fri, 22 Jul 2022 00:04:00 -0700
Subject: [PATCH] Don't clone the body of the matches (see
 dafny-lang/dafny#2334)

---
 Source/Dafny/Resolver.cs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Source/Dafny/Resolver.cs b/Source/Dafny/Resolver.cs
index 504631395e0..176c88b87dc 100644
--- a/Source/Dafny/Resolver.cs
+++ b/Source/Dafny/Resolver.cs
@@ -11958,7 +11958,7 @@ public RBranchStmt(IToken tok, int branchid, List<ExtendedPattern> patterns, Lis
 
       public RBranchStmt(int branchid, NestedMatchCaseStmt x, Attributes attrs = null) : base(x.Tok, branchid, new List<ExtendedPattern>()) {
         Contract.Requires(!(x.Pat is DisjunctivePattern)); // No nested or patterns
-        this.Body = new List<Statement>(x.Body); // Resolving the body will insert new elements. 
+        this.Body = new List<Statement>(x.Body); // Resolving the body will insert new elements.
         this.Attributes = attrs;
         this.Patterns.Add(x.Pat);
       }
@@ -12527,14 +12527,14 @@ private IEnumerable<ExtendedPattern> FlattenDisjunctivePatterns(ExtendedPattern
     private IEnumerable<NestedMatchCaseExpr> FlattenNestedMatchCaseExpr(NestedMatchCaseExpr c) {
       var cloner = new Cloner();
       foreach (var pat in FlattenDisjunctivePatterns(c.Pat)) {
-        yield return new NestedMatchCaseExpr(c.Tok, pat, cloner.CloneExpr(c.Body), cloner.CloneAttributes(c.Attributes));
+        yield return new NestedMatchCaseExpr(c.Tok, pat, c.Body, c.Attributes);
       }
     }
 
     private IEnumerable<NestedMatchCaseStmt> FlattenNestedMatchCaseStmt(NestedMatchCaseStmt c) {
       var cloner = new Cloner();
       foreach (var pat in FlattenDisjunctivePatterns(c.Pat)) {
-        yield return new NestedMatchCaseStmt(c.Tok, pat, c.Body.ConvertAll(cloner.CloneStmt), cloner.CloneAttributes(c.Attributes));
+        yield return new NestedMatchCaseStmt(c.Tok, pat, new List<Statement>(c.Body), c.Attributes);
       }
     }