fix: don't use with_selection_const in primary_drag

with_selection_const destroys the selection on movement errors.

closes #406

src/tui/editor.zig

@@ -627,7 +627,7 @@ pub const Editor = struct {
         Widget.need_render();
     }
 
-    pub fn buf_for_update(self: *Self) !*const Buffer {
+    pub fn buf_for_update(self: *Self) error{ Stop, OutOfMemory }!*const Buffer {
         if (!self.pause_undo) {
             self.cursels_saved.clearAndFree(self.allocator);
             self.cursels_saved = try self.cursels.clone(self.allocator);
@@ -635,19 +635,19 @@ pub const Editor = struct {
         return self.buffer orelse error.Stop;
     }
 
-    pub fn buf_root(self: *const Self) !Buffer.Root {
+    pub fn buf_root(self: *const Self) error{Stop}!Buffer.Root {
         return if (self.buffer) |p| p.root else error.Stop;
     }
 
-    fn buf_eol_mode(self: *const Self) !Buffer.EolMode {
+    fn buf_eol_mode(self: *const Self) error{Stop}!Buffer.EolMode {
         return if (self.buffer) |p| p.file_eol_mode else error.Stop;
     }
 
-    fn buf_utf8_sanitized(self: *const Self) !bool {
+    fn buf_utf8_sanitized(self: *const Self) error{Stop}!bool {
         return if (self.buffer) |p| p.file_utf8_sanitized else error.Stop;
     }
 
-    fn buf_a(self: *const Self) !Allocator {
+    fn buf_a(self: *const Self) error{Stop}!Allocator {
         return if (self.buffer) |p| p.allocator else error.Stop;
     }
 
@@ -2623,8 +2623,9 @@ pub const Editor = struct {
         primary.disable_selection(root, self.metrics);
         self.selection_mode = .word;
         primary.cursor.move_abs(root, &self.view, @intCast(y), @intCast(x), self.metrics) catch return;
-        _ = try self.select_word_at_cursor(primary);
+        self.selection_drag_initial = self.select_word_at_cursor(primary) catch |e| switch (e) {
-        self.selection_drag_initial = primary.selection;
+            error.Stop => primary.to_selection_normal(),
+        };
         self.collapse_cursors();
         self.clamp_mouse();
     }
@@ -2635,8 +2636,15 @@ pub const Editor = struct {
         primary.disable_selection(root, self.metrics);
         self.selection_mode = .line;
         primary.cursor.move_abs(root, &self.view, @intCast(y), @intCast(x), self.metrics) catch return;
-        try self.select_line_at_cursor(root, primary, .exclude_eol);
+        blk: {
+            self.select_line_at_cursor(root, primary, .exclude_eol) catch |e| switch (e) {
+                error.Stop => {
+                    self.selection_drag_initial = primary.to_selection_normal();
+                    break :blk;
+                },
+            };
             self.selection_drag_initial = primary.selection;
+        }
         self.collapse_cursors();
         self.clamp_mouse();
     }
@@ -2652,23 +2660,23 @@ pub const Editor = struct {
         switch (self.selection_mode) {
             .char => {},
             .word => {
-                if (sel.begin.right_of(sel.end)) {
+                if (sel.is_reversed()) {
                     sel.begin = initial.end;
-                    with_selection_const(root, move_cursor_word_begin, primary, self.metrics) catch {};
+                    move_cursor_word_begin(root, &sel.end, self.metrics) catch {};
                 } else {
                     sel.begin = initial.begin;
-                    with_selection_const(root, move_cursor_word_end, primary, self.metrics) catch {};
+                    move_cursor_word_end(root, &sel.end, self.metrics) catch {};
                 }
             },
             .line => {
-                if (sel.begin.right_of(sel.end)) {
+                if (sel.is_reversed()) {
                     sel.begin = initial.end;
-                    with_selection_const(root, move_cursor_begin, primary, self.metrics) catch {};
+                    move_cursor_begin(root, &sel.end, self.metrics) catch {};
                 } else {
                     sel.begin = initial.begin;
                     blk: {
-                        with_selection_const(root, move_cursor_end, primary, self.metrics) catch break :blk;
+                        move_cursor_end(root, &sel.end, self.metrics) catch break :blk;
-                        with_selection_const(root, move_cursor_right, primary, self.metrics) catch {};
+                        move_cursor_right(root, &sel.end, self.metrics) catch {};
                     }
                 }
             },
@@ -2840,8 +2848,8 @@ pub const Editor = struct {
     fn copy_word_at_cursor(self: *Self, text_allocator: Allocator) ![]const u8 {
         const root = try self.buf_root();
         const primary = self.get_primary();
-        const sel = if (primary.selection) |*sel| sel else try self.select_word_at_cursor(primary);
+        const sel = if (primary.selection) |sel| sel else try self.select_word_at_cursor(primary);
-        return try copy_selection(root, sel.*, text_allocator, self.metrics);
+        return try copy_selection(root, sel, text_allocator, self.metrics);
     }
 
     pub fn cut_selection(self: *Self, root: Buffer.Root, cursel: *CurSel, text_allocator: Allocator) !struct { []const u8, Buffer.Root } {
@@ -4531,7 +4539,7 @@ pub const Editor = struct {
     }
     pub const select_all_meta: Meta = .{ .description = "Select all" };
 
-    fn select_word_at_cursor(self: *Self, cursel: *CurSel) !*Selection {
+    fn select_word_at_cursor(self: *Self, cursel: *CurSel) error{Stop}!Selection {
         const root = try self.buf_root();
         const sel = cursel.enable_selection(root, self.metrics);
         defer cursel.check_selection(root, self.metrics);
@@ -4539,7 +4547,7 @@ pub const Editor = struct {
         try move_cursor_word_begin(root, &sel.begin, self.metrics);
         move_cursor_word_end(root, &sel.end, self.metrics) catch {};
         cursel.cursor = sel.end;
-        return sel;
+        return sel.*;
     }
 
     pub fn select_line_at_cursor(self: *Self, root: Buffer.Root, cursel: *CurSel, mode: enum { include_eol, exclude_eol, hold_cursor }) !void {

src/tui/mainview.zig

@@ -785,10 +785,10 @@ const cmds = struct {
 
             var existing = false;
             if (self.buffer_manager.get_buffer_for_file(file_path)) |new_buffer| {
-                if (new_buffer.is_dirty())
-                    return tp.exit("save as would overwrite unsaved changes");
                 if (buffer == new_buffer)
                     return tp.exit("same file");
+                if (new_buffer.is_dirty())
+                    return tp.exit("save as would overwrite unsaved changes");
                 existing = true;
             }
             try self.create_editor();