fix: fix Files double-click bug

programs/src/files/dnd.cpp

@@ -73,6 +73,13 @@ bool filemanager_dnd_mouse(Window* win, FileManagerState* fm, const FileManagerL
     }
     if (fm->drag_serial) return true;
 
+    // A fresh press means we missed the release of the armed one (focus
+    // went elsewhere mid-press); drop it and let this press be handled anew.
+    if (ev.left_pressed()) {
+        fm->press_idx = -1;
+        return false;
+    }
+
     int dx = x - fm->press_x;
     int dy = y - fm->press_y;
     if (dx * dx + dy * dy < DRAG_THRESHOLD * DRAG_THRESHOLD) return true;

programs/src/files/events.cpp

@@ -28,7 +28,8 @@ static bool filemanager_is_listing(const FileManagerState* fm) {
 // Left click on an entry. Ctrl toggles it, Shift selects the range from the
 // anchor (Ctrl+Shift adds that range); a plain click selects it alone, and a
 // second plain click within 400 ms opens it.
-static void filemanager_click_entry(FileManagerState* fm, int idx) {
+// True if the click opened the entry (the second click of a double-click).
+static bool filemanager_click_entry(FileManagerState* fm, int idx) {
     DesktopState* ds = fm->desktop;
     bool ctrl = ds && ds->kbd_ctrl_down;
     bool shift = ds && ds->kbd_shift_down;
@@ -38,7 +39,7 @@ static void filemanager_click_entry(FileManagerState* fm, int idx) {
         else filemanager_toggle_selection(fm, idx);
         fm->last_click_item = -1;
         fm->last_click_time = 0;
-        return;
+        return false;
     }
 
     uint64_t now = montauk::get_milliseconds();
@@ -46,11 +47,12 @@ static void filemanager_click_entry(FileManagerState* fm, int idx) {
         filemanager_open_entry(fm, idx);
         fm->last_click_item = -1;
         fm->last_click_time = 0;
-    } else {
-        filemanager_select_single(fm, idx);
-        fm->last_click_item = idx;
-        fm->last_click_time = now;
+        return true;
     }
+    filemanager_select_single(fm, idx);
+    fm->last_click_item = idx;
+    fm->last_click_time = now;
+    return false;
 }
 
 void filemanager_on_mouse(Window* win, MouseEvent& ev) {
@@ -290,9 +292,11 @@ void filemanager_on_mouse(Window* win, MouseEvent& ev) {
         if (in_view) {
             int clicked_idx = entry_at(local_x, local_y);
             if (clicked_idx >= 0) {
-                filemanager_click_entry(fm, clicked_idx);
-                // A press on a selected entry may turn into a drag.
-                if (filemanager_is_entry_selected(fm, clicked_idx)) {
+                // A press on a selected entry may turn into a drag, unless it
+                // opened the entry: the opened app takes focus, so we would
+                // never see the release.
+                bool opened = filemanager_click_entry(fm, clicked_idx);
+                if (!opened && filemanager_is_entry_selected(fm, clicked_idx)) {
                     fm->press_idx = clicked_idx;
                     fm->press_x = local_x;
                     fm->press_y = local_y;