fix a couple of issues with mention URIs

crates/acp_thread/src/mention.rs

@@ -135,10 +135,12 @@ impl MentionUri {
                 name,
                 line_range,
             } => {
+                let query = url::form_urlencoded::Serializer::new(String::new())
+                    .append_pair("symbol", name)
+                    .finish();
                 format!(
-                    "file://{}?symbol={}#L{}:{}",
+                    "file://{}?{query}#L{}:{}",
                     path.display(),
-                    name,
                     line_range.start + 1,
                     line_range.end + 1,
                 )
@@ -152,13 +154,22 @@ impl MentionUri {
                 )
             }
             MentionUri::Thread { name, id } => {
-                format!("zed:///agent/thread/{id}?name={name}")
+                let query = url::form_urlencoded::Serializer::new(String::new())
+                    .append_pair("name", name)
+                    .finish();
+                format!("zed:///agent/thread/{id}?{query}")
             }
             MentionUri::TextThread { path, name } => {
-                format!("zed:///agent/text-thread/{}?name={name}", path.display())
+                let query = url::form_urlencoded::Serializer::new(String::new())
+                    .append_pair("name", name)
+                    .finish();
+                format!("zed:///agent/text-thread/{}?{query}", path.display())
             }
             MentionUri::Rule { name, id } => {
-                format!("zed:///agent/rule/{id}?name={name}")
+                let query = url::form_urlencoded::Serializer::new(String::new())
+                    .append_pair("name", name)
+                    .finish();
+                format!("zed:///agent/rule/{id}?{query}")
             }
         }
     }

crates/agent_ui/src/acp/completion_provider.rs

@@ -688,29 +688,13 @@ impl ContextPickerCompletionProvider {
         workspace: Entity<Workspace>,
         cx: &mut App,
     ) -> Option<Completion> {
-        let path_prefix = workspace
+        let project = workspace.read(cx).project().clone();
-            .read(cx)
-            .project()
-            .read(cx)
-            .worktree_for_id(symbol.path.worktree_id, cx)?
-            .read(cx)
-            .root_name();
-
-        let (file_name, directory) =
-            crate::context_picker::file_context_picker::extract_file_name_and_directory(
-                &symbol.path.path,
-                path_prefix,
-            );
-        let full_path = if let Some(directory) = directory {
-            format!("{}{}", directory, file_name)
-        } else {
-            file_name.to_string()
-        };
 
         let label = CodeLabel::plain(symbol.name.clone(), None);
 
+        let abs_path = project.read(cx).absolute_path(&symbol.path, cx)?;
         let uri = MentionUri::Symbol {
-            path: full_path.into(),
+            path: abs_path,
             name: symbol.name.clone(),
             line_range: symbol.range.start.0.row..symbol.range.end.0.row,
         };