From de21e6ddb82bb0e6a9c7b5c7b9e997f48d3c3df8 Mon Sep 17 00:00:00 2001
From: Marcel Hollerbach <marcel-hollerbach@t-online.de>
Date: Sat, 12 Aug 2017 22:26:32 +0200
Subject: [PATCH] tiling: fix insertion in the tree

the problem here was that in the initial case the function got the
previous state of the tree wrong, so the insertion of a second client
ended up in a unpossible state of the tree, this should not happen
anymore now.

The insertion is now also way more stable, since in a errorcase the
client is not just not placed in the tree but associated with a window
tree, its just not placing the client in the window tree at all.
---
 src/modules/tiling/e_mod_tiling.c |  2 +-
 src/modules/tiling/window_tree.c  | 53 +++++++++++++++++--------------
 src/modules/tiling/window_tree.h  | 10 ++++++
 3 files changed, 41 insertions(+), 24 deletions(-)

diff --git a/src/modules/tiling/e_mod_tiling.c b/src/modules/tiling/e_mod_tiling.c
index 775e38a5c..3b86d33f1 100644
--- a/src/modules/tiling/e_mod_tiling.c
+++ b/src/modules/tiling/e_mod_tiling.c
@@ -703,7 +703,7 @@ _insert_client_prefered(E_Client *ec)
      }
    else
      {
-        _G.tinfo->tree = tiling_window_tree_insert(_G.tinfo->tree, _G.tinfo->tree, ec, _current_tiled_state(EINA_FALSE), EINA_FALSE);
+        _G.tinfo->tree = tiling_window_tree_insert(_G.tinfo->tree, NULL, ec, _current_tiled_state(EINA_FALSE), EINA_FALSE);
      }
 }
 
diff --git a/src/modules/tiling/window_tree.c b/src/modules/tiling/window_tree.c
index d0e61d5b6..b64a18889 100644
--- a/src/modules/tiling/window_tree.c
+++ b/src/modules/tiling/window_tree.c
@@ -95,13 +95,6 @@ _tiling_window_tree_split_type_get(Window_Tree *node)
 
 #define VERIFY_TYPE(t) if (t > TILING_SPLIT_VERTICAL || t < 0) { ERR("Invalid insert type"); return root; }
 
-#define ROOT_CHECK() \
-   if (!root) \
-     { \
-        new_node->weight = 1.0; \
-        return new_node; \
-     }
-
 Window_Tree *
 tiling_window_tree_insert(Window_Tree *root, Window_Tree *buddy,
                           E_Client *client, Tiling_Split_Type split_type, Eina_Bool before)
@@ -115,28 +108,42 @@ tiling_window_tree_insert(Window_Tree *root, Window_Tree *buddy,
    new_node = calloc(1, sizeof(*new_node));
    new_node->client = client;
 
-   ROOT_CHECK()
-
-   parent = buddy->parent;
-
-   if (!parent)
+   if (!root)
      {
-        //this means buddy is the root so just set buddy to NULL and parent to buddy
-        parent = buddy;
-        buddy = NULL;
-     }
+        root = calloc(1, sizeof(*root));
+        root->weight = 1.0;
 
-   parent_split_type = _tiling_window_tree_split_type_get(parent);
-
-   if (parent_split_type == split_type)
-     {
-        _tiling_window_tree_parent_add(parent, new_node, buddy, !before);
+        _tiling_window_tree_parent_add(root, new_node, NULL, !before);
      }
    else
      {
+        //if there is no buddy we are going to take the last child of the root
         if (!buddy)
-          buddy = root;
-        _tiling_window_tree_split_add(buddy, new_node, !before);
+          {
+             buddy = root;
+             do
+               {
+                  buddy = EINA_INLIST_CONTAINER_GET(eina_inlist_last(buddy->children), Window_Tree);
+               }
+             while (!buddy->client);
+          }
+        else
+          {
+             //make sure this buddy has a client,
+             EINA_SAFETY_ON_TRUE_RETURN_VAL(!buddy->client, root);
+          }
+
+        parent = buddy->parent;
+        parent_split_type = _tiling_window_tree_split_type_get(parent);
+
+        if (parent_split_type == split_type)
+          {
+             _tiling_window_tree_parent_add(parent, new_node, buddy, !before);
+          }
+        else
+          {
+             _tiling_window_tree_split_add(buddy, new_node, !before);
+          }
      }
 
    return root;
diff --git a/src/modules/tiling/window_tree.h b/src/modules/tiling/window_tree.h
index 93baba858..364305c3d 100644
--- a/src/modules/tiling/window_tree.h
+++ b/src/modules/tiling/window_tree.h
@@ -34,6 +34,16 @@ int          tiling_window_tree_edges_get(Window_Tree *node);
 void         tiling_window_tree_free(Window_Tree *root);
 void         tiling_window_tree_walk(Window_Tree *root, void (*func)(void *));
 
+/**
+ * Insert a new client into the tree
+ *
+ * @param root the root node where to insert in some subtree
+ * @param buddy the buddy where you want to place client to, buddy MUST be a node with a associated client OR NULL
+ * @param split_type the split type you want to insert the client
+ * @param before true to insert the client before the buddy false to insert it after the buddy
+ *
+ * @return the new root node
+ */
 Window_Tree *tiling_window_tree_insert(Window_Tree *root, Window_Tree *buddy,
                                        E_Client *client, Tiling_Split_Type split_type, Eina_Bool before);