Spawn the Open dialog without filename

src/arena/debug.rs

@@ -17,8 +17,9 @@ pub enum Arena {
 impl Drop for Arena {
     fn drop(&mut self) {
         if let Arena::Delegated { delegate, borrow } = self {
-            assert_eq!(*borrow, delegate.borrows.get());
-            delegate.borrows.update(|b| b - 1);
+            let borrows = delegate.borrows.get();
+            assert_eq!(*borrow, borrows);
+            delegate.borrows.set(borrows - 1);
         }
     }
 }

src/bin/edit/draw_editor.rs

@@ -260,10 +260,7 @@ pub fn draw_handle_wants_close(ctx: &mut Context, state: &mut State) {
 
     match action {
         Action::None => return,
-        Action::Save => {
-            state.file_picker_pending_name = doc.filename.clone();
-            state.wants_save = true;
-        }
+        Action::Save => state.wants_save = true,
         Action::Discard => state.documents.remove_active(),
         Action::Cancel => state.wants_exit = false,
     }

src/bin/edit/draw_filepicker.rs

@@ -13,9 +13,21 @@ use crate::loc::*;
 use crate::state::*;
 
 pub fn draw_file_picker(ctx: &mut Context, state: &mut State) {
+    // The save dialog is pre-filled with the current document filename.
+    if state.file_picker_pending_name.is_empty()
+        && state.wants_file_picker == StateFilePicker::SaveAs
+    {
+        state.file_picker_pending_name = state
+            .documents
+            .active()
+            .map_or("Untitled.txt", |doc| doc.filename.as_str())
+            .to_string();
+    }
+
     let width = (ctx.size().width - 20).max(10);
     let height = (ctx.size().height - 10).max(10);
     let mut doit = None;
+    let mut done = false;
 
     ctx.modal_begin(
         "file-picker",
@@ -110,7 +122,7 @@ pub fn draw_file_picker(ctx: &mut Context, state: &mut State) {
         }
     }
     if ctx.modal_end() {
-        state.wants_file_picker = StateFilePicker::None;
+        done = true;
     }
 
     if state.file_picker_overwrite_warning.is_some() {
@@ -157,19 +169,26 @@ pub fn draw_file_picker(ctx: &mut Context, state: &mut State) {
     }
 
     if let Some(path) = doit {
-        let res = if state.wants_file_picker == StateFilePicker::SaveAs {
-            if let Some(doc) = state.documents.active_mut() { doc.save(Some(path)) } else { Ok(()) }
-        } else {
+        let res = if state.wants_file_picker == StateFilePicker::Open {
             state.documents.add_file_path(&path).map(|_| ())
+        } else if let Some(doc) = state.documents.active_mut() {
+            doc.save(Some(path))
+        } else {
+            Ok(())
         };
         match res {
             Ok(..) => {
                 ctx.needs_rerender();
-                state.wants_file_picker = StateFilePicker::None;
+                done = true;
             }
             Err(err) => error_log_add(ctx, state, err),
         }
     }
+
+    if done {
+        state.wants_file_picker = StateFilePicker::None;
+        state.file_picker_pending_name = String::new();
+    }
 }
 
 // Returns Some(path) if the path refers to a file.

src/bin/edit/main.rs

@@ -243,21 +243,18 @@ fn handle_args(state: &mut State) -> apperr::Result<bool> {
         }
     }
 
-    let doc;
     if let Some(mut file) = sys::open_stdin_if_redirected() {
-        doc = state.documents.add_untitled()?;
+        let doc = state.documents.add_untitled()?;
         let mut tb = doc.buffer.borrow_mut();
         tb.read_file(&mut file, None)?;
         tb.mark_as_dirty();
     } else if let Some(path) = path {
-        doc = state.documents.add_file_path(&path)?;
+        state.documents.add_file_path(&path)?;
     } else {
-        doc = state.documents.add_untitled()?;
+        state.documents.add_untitled()?;
     }
 
     state.file_picker_pending_dir = DisplayablePathBuf::new(cwd);
-    state.file_picker_pending_name = doc.filename.clone();
-
     Ok(false)
 }
 

src/bin/edit/state.rs

@@ -121,7 +121,7 @@ pub struct State {
 
     pub wants_file_picker: StateFilePicker,
     pub file_picker_pending_dir: DisplayablePathBuf,
-    pub file_picker_pending_name: String, // This could be PathBuf, if `tui` would expose its TextBuffer for editline.
+    pub file_picker_pending_name: String,
     pub file_picker_entries: Option<Vec<DisplayablePathBuf>>,
     pub file_picker_overwrite_warning: Option<PathBuf>, // The path the warning is about.