editor: Fix selection direction reversal in SelectLargeSyntaxNode with multiple cursors (#51752)

Closes https://github.com/zed-industries/zed/issues/47737

Regressed by https://github.com/zed-industries/zed/pull/27295

Release Notes:

- Fixed an issue where using the `SelectLargeSyntaxNode` action with
multiple cursors could reverse the selection direction for the last
cursor.

crates/editor/src/editor.rs

@@ -16509,12 +16509,12 @@ impl Editor {
             .zip(new_selections.last().cloned())
             .expect("old_selections isn't empty");
 
-        // revert selection
-        let is_selection_reversed = {
-            let should_newest_selection_be_reversed = last_old.start != last_new.start;
-            new_selections.last_mut().expect("checked above").reversed =
-                should_newest_selection_be_reversed;
-            should_newest_selection_be_reversed
+        let is_selection_reversed = if new_selections.len() == 1 {
+            let should_be_reversed = last_old.start != last_new.start;
+            new_selections.last_mut().expect("checked above").reversed = should_be_reversed;
+            should_be_reversed
+        } else {
+            last_new.reversed
         };
 
         if selected_larger_node {

crates/editor/src/editor_tests.rs

@@ -10057,7 +10057,7 @@ async fn test_select_larger_smaller_syntax_node(cx: &mut TestAppContext) {
                 use mod1::mod2::{mod3, «mod4ˇ»};
 
                 fn fn_1«ˇ(param1: bool, param2: &str)» {
-                    let var1 = "«ˇtext»";
+                    let var1 = "«textˇ»";
                 }
             "#},
             cx,
@@ -10129,7 +10129,7 @@ async fn test_select_larger_smaller_syntax_node(cx: &mut TestAppContext) {
                 use mod1::mod2::{mod3, «mod4ˇ»};
 
                 fn fn_1«ˇ(param1: bool, param2: &str)» {
-                    let var1 = "«ˇtext»";
+                    let var1 = "«textˇ»";
                 }
             "#},
             cx,
@@ -10198,7 +10198,32 @@ async fn test_select_larger_smaller_syntax_node(cx: &mut TestAppContext) {
                 use mod1::mod2::«{mod3, mod4}ˇ»;
 
                 fn fn_1«ˇ(param1: bool, param2: &str)» {
-                    let var1 = "«ˇtext»";
+                    let var1 = "«textˇ»";
+                }
+            "#},
+            cx,
+        );
+    });
+
+    // Ensure multiple cursors have consistent direction after expanding
+    editor.update_in(cx, |editor, window, cx| {
+        editor.unfold_all(&UnfoldAll, window, cx);
+        editor.change_selections(SelectionEffects::no_scroll(), window, cx, |s| {
+            s.select_display_ranges([
+                DisplayPoint::new(DisplayRow(0), 25)..DisplayPoint::new(DisplayRow(0), 25),
+                DisplayPoint::new(DisplayRow(3), 18)..DisplayPoint::new(DisplayRow(3), 18),
+            ]);
+        });
+        editor.select_larger_syntax_node(&SelectLargerSyntaxNode, window, cx);
+    });
+    editor.update(cx, |editor, cx| {
+        assert_text_with_selections(
+            editor,
+            indoc! {r#"
+                use mod1::mod2::{mod3, «mod4ˇ»};
+
+                fn fn_1(param1: bool, param2: &str) {
+                    let var1 = "«textˇ»";
                 }
             "#},
             cx,