[xbuild] Add PreserveExistingMetadata property to CreateItem task

This property is exists since .NET 3.5 and enables preservation
of existing metadata while setting new metadata on items via the
AdditionalMetadata property.

diff --git a/mcs/class/Microsoft.Build.Tasks/Microsoft.Build.Tasks/CreateItem.cs b/mcs/class/Microsoft.Build.Tasks/Microsoft.Build.Tasks/CreateItem.cs
index 1c7463e50c1ee2abba3c87cc9423ec443f6fd856..187ca0c31f0dc9890acb51ec1303678c1816cd99 100644 (file)
--- a/mcs/class/Microsoft.Build.Tasks/Microsoft.Build.Tasks/CreateItem.cs
+++ b/mcs/class/Microsoft.Build.Tasks/Microsoft.Build.Tasks/CreateItem.cs
@@ -38,7 +38,8 @@ namespace Microsoft.Build.Tasks {
                string[]        additionalMetadata;
                ITaskItem[]     exclude;
                ITaskItem[]     include;
-       
+               bool            preserveExistingMetadata;
+
                public CreateItem ()
                {
                }
@@ -65,8 +66,12 @@ namespace Microsoft.Build.Tasks {
                                foreach (string metadata in AdditionalMetadata) {
                                        //a=1
                                        string [] parts = metadata.Split (new char [] {'='}, 2, StringSplitOptions.RemoveEmptyEntries);
-                                       if (parts.Length == 2)
-                                               matchedItem.SetMetadata (parts [0].Trim (), parts [1].Trim ());
+                                       if (parts.Length == 2) {
+                                               string name = parts [0].Trim ();
+                                               string oldValue = matchedItem.GetMetadata (name);
+                                               if (!preserveExistingMetadata || string.IsNullOrEmpty (oldValue))
+                                                       matchedItem.SetMetadata (name, parts [1].Trim ());
+                                       }
                                }
                        }
 
@@ -90,6 +95,13 @@ namespace Microsoft.Build.Tasks {
                        get { return include; }
                        set { include = value; }
                }
+
+#if NET_3_5
+               public bool PreserveExistingMetadata {
+                       get { return preserveExistingMetadata; }
+                       set { preserveExistingMetadata = value; }
+               }
+#endif
        }
 }