vim: Keep command palette matches next to filename completions

With vim or helix mode on, searching the command palette for "split
selection" showed only a `:split selection` entry and hid
`editor: split selection into lines`. The vim interceptor reads the query
as `:split <file>`, and its filename completions were marked exclusive,
which drops every regular match. The same happens for other searches
that start with a filename command, like "edit prediction".

Return the completions as non-exclusive, like every other intercepted
command. They are still listed first, so `:sp foo` + enter behaves the
same.

Closes #64431

crates/vim/src/command.rs

@@ -2023,9 +2023,11 @@ pub fn command_interceptor(
                     positions,
                 });
             }
+            // Palette searches like "split selection" or "edit prediction" also
+            // parse as a command with a filename, so keep the regular matches.
             CommandInterceptResult {
                 results,
-                exclusive: true,
+                exclusive: false,
             }
         })
     } else {
@@ -2634,6 +2636,7 @@ mod test {
 
     use crate::{
         VimAddon,
+        command::command_interceptor,
         state::Mode,
         test::{NeovimBackedTestContext, VimTestContext},
     };
@@ -2984,6 +2987,28 @@ mod test {
         });
     }
 
+    #[gpui::test]
+    async fn test_filename_completions_keep_palette_matches(cx: &mut TestAppContext) {
+        let mut cx = VimTestContext::new(cx, true).await;
+        let workspace = cx.workspace(|_, _, cx| cx.weak_entity());
+
+        let intercept_result = cx
+            .update(|_, cx| command_interceptor("split selection", workspace, cx))
+            .await;
+
+        assert_eq!(
+            intercept_result
+                .results
+                .first()
+                .map(|item| item.string.as_str()),
+            Some(":split selection")
+        );
+        assert!(
+            !intercept_result.exclusive,
+            "filename completions must not hide the regular command palette matches"
+        );
+    }
+
     #[gpui::test]
     async fn test_command_write_filename(cx: &mut TestAppContext) {
         let mut cx = VimTestContext::new(cx, true).await;