apply updated workspace gap assignments after reload (#5279)

Fixes https://github.com/i3/i3/issues/5257

include/gaps.h

@@ -26,3 +26,16 @@ bool gaps_should_inset_con(Con *con, int children);
  * the container is not touching the edge of the screen in that direction.
  */
 bool gaps_has_adjacent_container(Con *con, direction_t direction);
+
+/**
+ * Returns the configured gaps for this workspace based on the workspace name,
+ * number, and configured workspace gap assignments.
+ */
+gaps_t gaps_for_workspace(Con *ws);
+
+/**
+ * Re-applies all workspace gap assignments to existing workspaces after
+ * reloading the configuration file.
+ *
+ */
+void gaps_reapply_workspace_assignments(void);

src/config.c

@@ -296,11 +296,11 @@ bool load_configuration(const char *override_configpath, config_load_t load_type
         translate_keysyms();
         grab_all_keys(conn);
         regrab_all_buttons(conn);
+        gaps_reapply_workspace_assignments();
 
         /* Redraw the currently visible decorations on reload, so that the
          * possibly new drawing parameters changed. */
-        x_deco_recurse(croot);
-        xcb_flush(conn);
+        tree_render();
     }
 
     return result == 0;

src/gaps.c

@@ -110,3 +110,54 @@ bool gaps_has_adjacent_container(Con *con, direction_t direction) {
     /* For fullscreen containers, only consider the adjacent container if it is also fullscreen. */
     return con_has_parent(con, fullscreen) && con_has_parent(second, fullscreen);
 }
+
+/*
+ * Returns the configured gaps for this workspace based on the workspace name,
+ * number, and configured workspace gap assignments.
+ */
+gaps_t gaps_for_workspace(Con *ws) {
+    gaps_t gaps = (gaps_t){0, 0, 0, 0, 0};
+    struct Workspace_Assignment *assignment;
+    TAILQ_FOREACH (assignment, &ws_assignments, ws_assignments) {
+        if (strcmp(assignment->name, ws->name) == 0) {
+            gaps = assignment->gaps;
+            break;
+        } else if (ws->num != -1 && name_is_digits(assignment->name) && ws_name_to_number(assignment->name) == ws->num) {
+            gaps = assignment->gaps;
+        }
+    }
+
+    if (gaps.inner != 0) {
+        gaps.inner -= config.gaps.inner;
+    }
+    if (gaps.top != 0) {
+        gaps.top -= config.gaps.top;
+    }
+    if (gaps.right != 0) {
+        gaps.right -= config.gaps.right;
+    }
+    if (gaps.bottom != 0) {
+        gaps.bottom -= config.gaps.bottom;
+    }
+    if (gaps.left != 0) {
+        gaps.left -= config.gaps.left;
+    }
+
+    return gaps;
+}
+
+/*
+ * Re-applies all workspace gap assignments to existing workspaces after
+ * reloading the configuration file.
+ *
+ */
+void gaps_reapply_workspace_assignments(void) {
+    Con *output, *workspace = NULL;
+    TAILQ_FOREACH (output, &(croot->nodes_head), nodes) {
+        Con *content = output_get_content(output);
+        TAILQ_FOREACH (workspace, &(content->nodes_head), nodes) {
+            DLOG("updating gap assignments for workspace %s\n", workspace->name);
+            workspace->gaps = gaps_for_workspace(workspace);
+        }
+    }
+}

src/workspace.c

@@ -135,38 +135,11 @@ Con *workspace_get(const char *num) {
     }
 
     LOG("Creating new workspace \"%s\"\n", num);
-    gaps_t gaps = (gaps_t){0, 0, 0, 0, 0};
 
     /* We set workspace->num to the number if this workspace’s name begins with
      * a positive number. Otherwise it’s a named ws and num will be 1. */
     const int parsed_num = ws_name_to_number(num);
 
-    struct Workspace_Assignment *assignment;
-    TAILQ_FOREACH (assignment, &ws_assignments, ws_assignments) {
-        if (strcmp(assignment->name, num) == 0) {
-            gaps = assignment->gaps;
-            break;
-        } else if (parsed_num != -1 && name_is_digits(assignment->name) && ws_name_to_number(assignment->name) == parsed_num) {
-            gaps = assignment->gaps;
-        }
-    }
-
-    if (gaps.inner != 0) {
-        gaps.inner -= config.gaps.inner;
-    }
-    if (gaps.top != 0) {
-        gaps.top -= config.gaps.top;
-    }
-    if (gaps.right != 0) {
-        gaps.right -= config.gaps.right;
-    }
-    if (gaps.bottom != 0) {
-        gaps.bottom -= config.gaps.bottom;
-    }
-    if (gaps.left != 0) {
-        gaps.left -= config.gaps.left;
-    }
-
     Con *output = get_assigned_output(num, parsed_num);
     /* if an assignment is not found, we create this workspace on the current output */
     if (!output) {
@@ -187,7 +160,7 @@ Con *workspace_get(const char *num) {
     workspace->workspace_layout = config.default_layout;
     workspace->num = parsed_num;
     workspace->type = CT_WORKSPACE;
-    workspace->gaps = gaps;
+    workspace->gaps = gaps_for_workspace(workspace);
 
     con_attach(workspace, output_get_content(output), false);
     _workspace_apply_default_orientation(workspace);
@@ -314,14 +287,6 @@ Con *create_workspace_on_output(Output *output, Con *content) {
         sasprintf(&(ws->name), "%d", c);
     }
 
-    struct Workspace_Assignment *assignment;
-    TAILQ_FOREACH (assignment, &ws_assignments, ws_assignments) {
-        if (strcmp(assignment->name, ws->name) == 0) {
-            ws->gaps = assignment->gaps;
-            break;
-        }
-    }
-
     con_attach(ws, content, false);
 
     char *name;
@@ -329,6 +294,8 @@ Con *create_workspace_on_output(Output *output, Con *content) {
     x_set_name(ws, name);
     free(name);
 
+    ws->gaps = gaps_for_workspace(ws);
+
     ws->fullscreen_mode = CF_OUTPUT;
 
     ws->workspace_layout = config.default_layout;

testcases/t/319-gaps.t

@@ -18,6 +18,7 @@
 # Ticket: #3724
 
 use i3test i3_autostart => 0;
+use i3test::Util qw(slurp);
 
 my $config = <<EOT;
 # i3 config file (v4)
@@ -233,4 +234,53 @@ is_deeply(scalar $floating->rect, $orig_rect, 'floating window position unchange
 
 exit_gracefully($pid);
 
+################################################################################
+# Ensure existing workspaces pick up changes in gap assignments (issue #5257).
+################################################################################
+
+$config = <<EOT;
+# i3 config file (v4)
+font -misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1
+
+gaps inner 10
+
+default_border pixel 0
+EOT
+
+$pid = launch_with_config($config);
+
+cmd 'workspace 2';
+
+$left = open_window;
+$right = open_window;
+sync_with_i3;
+
+is_gaps();
+
+my $version = i3()->get_version()->recv;
+open(my $configfh, '>', $version->{'loaded_config_file_name'});
+say $configfh <<EOT;
+# i3 config file (v4)
+font -misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1
+
+# Increase gaps for (existing) workspace 2 to 16px
+workspace 2 gaps inner 16
+gaps inner 10
+
+default_border pixel 0
+EOT
+close($configfh);
+
+cmd 'reload';
+
+sync_with_i3;
+
+$inner_gaps = 16;
+$outer_gaps = 0;
+$total_gaps = $outer_gaps + $inner_gaps;
+
+is_gaps();
+
+exit_gracefully($pid);
+
 done_testing;