cmd_focus_sibling: Fix crash on workspace level

Fixes #3997

2 files changed, 22 insertions, 1 deletions

diff --git a/src/commands.c b/src/commands.c
index 897ba288..14bd877d 100644
--- a/src/commands.c
+++ b/src/commands.c
@@ -1299,7 +1299,16 @@ void cmd_focus_sibling(I3_CMD, const char *direction_str) {
         }
         Con *next = get_tree_next_sibling(current->con, direction);
         if (next) {
-            con_activate(next);
+            if (next->type == CT_WORKSPACE) {
+                /* On the workspace level, we need to make sure that the
+                 * workspace change happens properly. However, workspace_show
+                 * descends focus so we also have to put focus on the workspace
+                 * itself to maintain consistency. See #3997. */
+                workspace_show(next);
+                con_focus(next);
+            } else {
+                con_activate(next);
+            }
         }
     }
 
diff --git a/testcases/t/307-focus-next-prev.t b/testcases/t/307-focus-next-prev.t
index c7f06589..4f8a8ecd 100644
--- a/testcases/t/307-focus-next-prev.t
+++ b/testcases/t/307-focus-next-prev.t
@@ -69,4 +69,16 @@ cmp_tree(
         cmd 'focus parent, focus next sibling';
     });
 
+# See #3997
+cmd 'workspace 2';
+open_window;
+cmd 'workspace 1';
+open_window;
+cmd 'focus parent, focus parent, focus next sibling, focus prev sibling';
+does_i3_live;
+is(focused_ws, '1', 'Back and forth between workspaces');
+
+cmd 'focus parent, focus parent, focus next sibling';
+is(focused_ws, '2', "Workspace 2 focused with 'focus next sibling'");
+
 done_testing;