CSharp: Add support for source groups with out-of-source builds

This also fixes support for multiple sources of the same name in
different directories.  Add a test for both problems.

Issue: #19505

3 files changed, 17 insertions, 4 deletions

diff --git a/Tests/CSharpOnly/CMakeLists.txt b/Tests/CSharpOnly/CMakeLists.txt
index 82049c7..42cbe2e 100644
--- a/Tests/CSharpOnly/CMakeLists.txt
+++ b/Tests/CSharpOnly/CMakeLists.txt
@@ -2,7 +2,9 @@
 project (CSharpOnly CSharp)
 
 # C# does not make any difference between STATIC and SHARED libs
-add_library(lib1 STATIC lib1.cs)
+add_library(lib1 STATIC lib1.cs nested/lib1.cs)
+#without the source group this test will fail to compile
+source_group(nested FILES nested/lib1.cs)
 add_library(lib2 SHARED lib2.cs)
 
 add_executable(CSharpOnly csharponly.cs)
diff --git a/Tests/CSharpOnly/csharponly.cs b/Tests/CSharpOnly/csharponly.cs
index ad4641a..3890c82 100644
--- a/Tests/CSharpOnly/csharponly.cs
+++ b/Tests/CSharpOnly/csharponly.cs
@@ -5,10 +5,8 @@ namespace CSharpOnly
         public static void Main(string[] args)
         {
             int val = Lib1.getResult();
-
             Lib2 l = new Lib2();
-            val = l.myVal;
-
+            val = val +  l.myVal + nested.Lib1.getResult();
             return;
         }
     }
diff --git a/Tests/CSharpOnly/nested/lib1.cs b/Tests/CSharpOnly/nested/lib1.cs
new file mode 100644
index 0000000..c2fde4b
--- /dev/null
+++ b/Tests/CSharpOnly/nested/lib1.cs
@@ -0,0 +1,13 @@
+namespace CSharpOnly
+{
+    namespace nested
+    {
+        public class Lib1
+        {
+            public static int getResult()
+            {
+                return 23;
+            }
+        }
+    }
+}