Clone shared members list before operators merging. Fixes #10967

[mono.git] / mcs / mcs / membercache.cs

diff --git a/mcs/mcs/membercache.cs b/mcs/mcs/membercache.cs
index 7209af7dc74c5fcbe93d50e9eb6ec8f3bfceadfd..cad910e01bc896b209a8c150e094a23a5513b660 100644 (file)
--- a/mcs/mcs/membercache.cs
+++ b/mcs/mcs/membercache.cs
@@ -299,6 +299,7 @@ namespace Mono.CSharp {
                        if (member.Kind == MemberKind.Operator) {
                                var dt = member.DeclaringType;
 
+
                                //
                                // Some core types have user operators but they cannot be used like normal
                                // user operators as they are predefined and therefore having different
@@ -908,7 +909,7 @@ namespace Mono.CSharp {
                public static IList<MemberSpec> GetUserOperator (TypeSpec container, Operator.OpType op, bool declaredOnly)
                {
                        IList<MemberSpec> found = null;
-
+                       bool shared_list = true;
                        IList<MemberSpec> applicable;
                        do {
                                var mc = container.MemberCache;
@@ -938,10 +939,13 @@ namespace Mono.CSharp {
                                                                        found = new List<MemberSpec> ();
                                                                        found.Add (applicable[i]);
                                                                } else {
-                                                                       var prev = found as List<MemberSpec>;
-                                                                       if (prev == null) {
+                                                                       List<MemberSpec> prev;
+                                                                       if (shared_list) {
+                                                                               shared_list = false;
                                                                                prev = new List<MemberSpec> (found.Count + 1);
                                                                                prev.AddRange (found);
+                                                                       } else {
+                                                                               prev = (List<MemberSpec>) found;
                                                                        }
 
                                                                        prev.Add (applicable[i]);
@@ -950,12 +954,16 @@ namespace Mono.CSharp {
                                                } else {
                                                        if (found == null) {
                                                                found = applicable;
+                                                               shared_list = true;
                                                        } else {
-                                                               var merged = found as List<MemberSpec>;
-                                                               if (merged == null) {
+                                                               List<MemberSpec> merged;
+                                                               if (shared_list) {
+                                                                       shared_list = false;
                                                                        merged = new List<MemberSpec> (found.Count + applicable.Count);
                                                                        merged.AddRange (found);
                                                                        found = merged;
+                                                               } else {
+                                                                       merged = (List<MemberSpec>) found;
                                                                }
 
                                                                merged.AddRange (applicable);