Disable deleting from an empty buffer which can cause a crash.

helix-term/src/commands.rs

@@ -745,6 +745,10 @@ pub fn extend_line(cx: &mut Context) {
 // heuristic: append changes to history after each command, unless we're in insert mode
 
 fn _delete_selection(doc: &mut Document, view_id: ViewId) {
+    if doc.empty() {
+        return;
+    }
+
     // first yank the selection
     let values: Vec<String> = doc
         .selection(view_id)

helix-view/src/document.rs

@@ -494,6 +494,10 @@ impl Document {
     pub fn versioned_identifier(&self) -> lsp::VersionedTextDocumentIdentifier {
         lsp::VersionedTextDocumentIdentifier::new(self.url().unwrap(), self.version)
     }
+
+    pub fn empty(&self) -> bool {
+        self.text == "\n"
+    }
 }
 
 #[cfg(test)]