2 files changed, 15 insertions, 1 deletions

diff --git a/crates/ra_vfs/src/lib.rs b/crates/ra_vfs/src/lib.rs
index d1b0222e7..70a13f765 100644
--- a/crates/ra_vfs/src/lib.rs
+++ b/crates/ra_vfs/src/lib.rs
@@ -264,7 +264,9 @@ impl Vfs {
                 self.pending_changes.push(change);
             }
             TaskResult::AddSingleFile { root, path, text } => {
-                self.do_add_file(root, path, text, false);
+                if self.find_file(root, &path).is_none() {
+                    self.do_add_file(root, path, text, false);
+                }
             }
             TaskResult::ChangeSingleFile { root, path, text } => {
                 if let Some(file) = self.find_file(root, &path) {
diff --git a/crates/ra_vfs/tests/vfs.rs b/crates/ra_vfs/tests/vfs.rs
index 357e1c775..545e1dbdd 100644
--- a/crates/ra_vfs/tests/vfs.rs
+++ b/crates/ra_vfs/tests/vfs.rs
@@ -165,6 +165,18 @@ fn test_vfs_works() -> std::io::Result<()> {
         assert_eq!(path, "sub1/sub2/new1.rs")
     );
 
+    {
+        vfs.add_file_overlay(&dir.path().join("a/memfile.rs"), "memfile".to_string());
+        assert_match!(
+            vfs.commit_changes().as_slice(),
+            [VfsChange::AddFile { text, .. }],
+            assert_eq!(text.as_str(), "memfile")
+        );
+        fs::write(&dir.path().join("a/memfile.rs"), "ignore me").unwrap();
+        process_tasks(&mut vfs, 1);
+        assert_match!(vfs.commit_changes().as_slice(), []);
+    }
+
     // should be ignored
     fs::create_dir_all(dir.path().join("a/target")).unwrap();
     fs::write(&dir.path().join("a/target/new.rs"), "ignore me").unwrap();