From e6ca7ca06f585fa22662443275d44a407f366c9d Mon Sep 17 00:00:00 2001
From: Albert Safin <xzfcpw@gmail.com>
Date: Wed, 19 Feb 2020 00:48:31 +0000
Subject: [PATCH 1/2] Sanitize con and window rect dimensions

Make sure they're neither zero (prohibited by X11) nor overflown during
subtraction.
---
 include/util.h | 1 +
 src/render.c   | 4 ++++
 src/util.c     | 6 ++++++
 3 files changed, 11 insertions(+)

diff --git a/include/util.h b/include/util.h
index 68b3c68f..8459db10 100644
--- a/include/util.h
+++ b/include/util.h
@@ -65,6 +65,7 @@ bool rect_contains(Rect rect, uint32_t x, uint32_t y);
 Rect rect_add(Rect a, Rect b);
 Rect rect_sub(Rect a, Rect b);
 bool rect_equals(Rect a, Rect b);
+Rect rect_sanitize_dimensions(Rect rect);
 
 /**
  * Returns true if the name consists of only digits.
diff --git a/src/render.c b/src/render.c
index 112268cc..40704f52 100644
--- a/src/render.c
+++ b/src/render.c
@@ -64,6 +64,8 @@ void render_con(Con *con) {
         inset->width -= (2 * con->border_width);
         inset->height -= (2 * con->border_width);
 
+        *inset = rect_sanitize_dimensions(*inset);
+
         /* NB: We used to respect resize increment size hints for tiling
          * windows up until commit 0db93d9 here. However, since all terminal
          * emulators cope with ignoring the size hints in a better way than we
@@ -121,6 +123,8 @@ void render_con(Con *con) {
                 render_con_dockarea(con, child, &params);
             }
 
+            child->rect = rect_sanitize_dimensions(child->rect);
+
             DLOG("child at (%d, %d) with (%d x %d)\n",
                  child->rect.x, child->rect.y, child->rect.width, child->rect.height);
             x_raise_con(child);
diff --git a/src/util.c b/src/util.c
index e9df9575..969dc2a2 100644
--- a/src/util.c
+++ b/src/util.c
@@ -53,6 +53,12 @@ Rect rect_sub(Rect a, Rect b) {
                   a.height - b.height};
 }
 
+Rect rect_sanitize_dimensions(Rect rect) {
+    rect.width = (int32_t)rect.width <= 0 ? 1 : rect.width;
+    rect.height = (int32_t)rect.height <= 0 ? 1 : rect.height;
+    return rect;
+}
+
 bool rect_equals(Rect a, Rect b) {
     return a.x == b.x && a.y == b.y && a.width == b.width && a.height == b.height;
 }

From 670c23600f30a5f0e417c0d3d256356c73e149b4 Mon Sep 17 00:00:00 2001
From: Albert Safin <xzfcpw@gmail.com>
Date: Wed, 19 Feb 2020 01:07:05 +0000
Subject: [PATCH 2/2] Decoration click/mouse move: iterate children in reverse
 order

In the case of decoration overlap, we should handle the one that is
drawn on top, i.e., the last one.
---
 src/click.c    | 2 +-
 src/handlers.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/click.c b/src/click.c
index e5dcfa92..19076252 100644
--- a/src/click.c
+++ b/src/click.c
@@ -361,7 +361,7 @@ int handle_button_press(xcb_button_press_event_t *event) {
 
     /* Check if the click was on the decoration of a child */
     Con *child;
-    TAILQ_FOREACH (child, &(con->nodes_head), nodes) {
+    TAILQ_FOREACH_REVERSE (child, &(con->nodes_head), nodes_head, nodes) {
         if (!rect_contains(child->deco_rect, event->event_x, event->event_y))
             continue;
 
diff --git a/src/handlers.c b/src/handlers.c
index 79e5329b..7926fec5 100644
--- a/src/handlers.c
+++ b/src/handlers.c
@@ -160,7 +160,7 @@ static void handle_enter_notify(xcb_enter_notify_event_t *event) {
     layout_t layout = (enter_child ? con->parent->layout : con->layout);
     if (layout == L_DEFAULT) {
         Con *child;
-        TAILQ_FOREACH (child, &(con->nodes_head), nodes) {
+        TAILQ_FOREACH_REVERSE (child, &(con->nodes_head), nodes_head, nodes) {
             if (rect_contains(child->deco_rect, event->event_x, event->event_y)) {
                 LOG("using child %p / %s instead!\n", child, child->name);
                 con = child;
@@ -217,7 +217,7 @@ static void handle_motion_notify(xcb_motion_notify_event_t *event) {
 
     /* see over which rect the user is */
     Con *current;
-    TAILQ_FOREACH (current, &(con->nodes_head), nodes) {
+    TAILQ_FOREACH_REVERSE (current, &(con->nodes_head), nodes_head, nodes) {
         if (!rect_contains(current->deco_rect, event->event_x, event->event_y))
             continue;