diff --git a/.gitlab/issue_templates/Bug.md b/.gitlab/issue_templates/Bug.md
index 61244a93c4..4a47d30574 100644
--- a/.gitlab/issue_templates/Bug.md
+++ b/.gitlab/issue_templates/Bug.md
@@ -1,4 +1,13 @@
+<!--
+  Please, read the CONTRIBUTING.md guide on how to file a new issue.
+
+  https://gitlab.gnome.org/GNOME/gtk/-/blob/master/CONTRIBUTING.md
+-->
 ## Steps to reproduce
+<!--
+  Please, explain the sequence of actions necessary to reproduce the
+  bug
+-->
 
  1. ...
  2. ...
@@ -32,5 +41,8 @@
 ## Additional information
 <!--
  - Screenshots or screen recordings are useful for visual errors
+  - Attaching a screenshot or a video without explaining the current
+    behavior and the actions necessary to reproduce the bug will lead
+    to the bug being closed
  - Please report any warning or message printed on the terminal
 -->
diff --git a/.gitlab/issue_templates/Crash.md b/.gitlab/issue_templates/Crash.md
index a2531687cf..2948affe1c 100644
--- a/.gitlab/issue_templates/Crash.md
+++ b/.gitlab/issue_templates/Crash.md
@@ -1,4 +1,14 @@
+<!--
+  Please, read the CONTRIBUTING.md guide on how to file a new issue.
+
+  https://gitlab.gnome.org/GNOME/gtk/-/blob/master/CONTRIBUTING.md
+-->
+
 ## Steps to reproduce
+<!--
+  Please, explain the sequence of actions necessary to reproduce the
+  crash
+-->
 
  1. ...
  2. ...
diff --git a/gdk/wayland/gdkdisplay-wayland.c b/gdk/wayland/gdkdisplay-wayland.c
index f5ea972fa2..3acc10ed50 100644
--- a/gdk/wayland/gdkdisplay-wayland.c
+++ b/gdk/wayland/gdkdisplay-wayland.c
@@ -1350,21 +1350,23 @@ _gdk_wayland_display_create_shm_surface (GdkWaylandDisplay *display,
   data->buffer = NULL;
   data->scale = scale;
 
-  stride = cairo_format_stride_for_width (CAIRO_FORMAT_ARGB32, width*scale);
+  stride = cairo_format_stride_for_width (CAIRO_FORMAT_ARGB32, width * scale);
 
   data->pool = create_shm_pool (display->shm,
-                                height*scale*stride,
+                                height * scale * stride,
                                 &data->buf_length,
                                 &data->buf);
+  if (G_UNLIKELY (data->pool == NULL))
+    g_error ("Unable to create shared memory pool");
 
   surface = cairo_image_surface_create_for_data (data->buf,
                                                  CAIRO_FORMAT_ARGB32,
-                                                 width*scale,
-                                                 height*scale,
+                                                 width * scale,
+                                                 height * scale,
                                                  stride);
 
   data->buffer = wl_shm_pool_create_buffer (data->pool, 0,
-                                            width*scale, height*scale,
+                                            width * scale, height * scale,
                                             stride, WL_SHM_FORMAT_ARGB8888);
 
   cairo_surface_set_user_data (surface, &gdk_wayland_shm_surface_cairo_key,
diff --git a/gtk/gtkliststore.c b/gtk/gtkliststore.c
index b1fa81e777..1b17843a97 100644
--- a/gtk/gtkliststore.c
+++ b/gtk/gtkliststore.c
@@ -2149,7 +2149,7 @@ gtk_list_store_has_default_sort_func (GtkTreeSortable *sortable)
 /**
  * gtk_list_store_insert_with_values:
  * @list_store: A #GtkListStore
- * @iter: (out) (allow-none): An unset #GtkTreeIter to set to the new row, or %NULL
+ * @iter: (out) (optional): An unset #GtkTreeIter to set to the new row
  * @position: position to insert the new row, or -1 to append after existing
  *     rows
  * @...: pairs of column number and value, terminated with -1
@@ -2161,7 +2161,8 @@ gtk_list_store_has_default_sort_func (GtkTreeSortable *sortable)
  *
  * Calling
  * `gtk_list_store_insert_with_values (list_store, iter, position...)`
- * has the same effect as calling
+ * has the same effect as calling:
+ *
  * |[<!-- language="C" -->
  * static void
  * insert_value (GtkListStore *list_store,
@@ -2175,12 +2176,15 @@ gtk_list_store_has_default_sort_func (GtkTreeSortable *sortable)
  *                       );
  * }
  * ]|
- * with the difference that the former will only emit a row_inserted signal,
- * while the latter will emit row_inserted, row_changed and, if the list store
- * is sorted, rows_reordered. Since emitting the rows_reordered signal
- * repeatedly can affect the performance of the program,
- * gtk_list_store_insert_with_values() should generally be preferred when
- * inserting rows in a sorted list store.
+ *
+ * with the difference that the former will only emit #GtkTreeModel::row-inserted
+ * once, while the latter will emit #GtkTreeModel::row-inserted,
+ * #GtkTreeModel::row-changed and, if the list store is sorted,
+ * #GtkTreeModel::rows-reordered for every inserted value.
+ *
+ * Since emitting the #GtkTreeModel::rows-reordered signal repeatedly can
+ * affect the performance of the program, gtk_list_store_insert_with_values()
+ * should generally be preferred when inserting rows in a sorted list store.
  */
 void
 gtk_list_store_insert_with_values (GtkListStore *list_store,
@@ -2244,9 +2248,9 @@ gtk_list_store_insert_with_values (GtkListStore *list_store,
 
 
 /**
- * gtk_list_store_insert_with_valuesv:
+ * gtk_list_store_insert_with_valuesv: (rename-to gtk_list_store_insert_with_values)
  * @list_store: A #GtkListStore
- * @iter: (out) (allow-none): An unset #GtkTreeIter to set to the new row, or %NULL.
+ * @iter: (out) (optional): An unset #GtkTreeIter to set to the new row
  * @position: position to insert the new row, or -1 for last
  * @columns: (array length=n_values): an array of column numbers
  * @values: (array length=n_values): an array of GValues 
@@ -2254,8 +2258,9 @@ gtk_list_store_insert_with_values (GtkListStore *list_store,
  * 
  * A variant of gtk_list_store_insert_with_values() which
  * takes the columns and values as two arrays, instead of
- * varargs. This function is mainly intended for 
- * language-bindings.
+ * varargs.
+ *
+ * This function is mainly intended for language-bindings.
  */
 void
 gtk_list_store_insert_with_valuesv (GtkListStore *list_store,