schema compile FEATURE ordered augment connect

When there are augments from several modules
to one node, they are ordered based on their
module name. The point is only to make sure
the augments are always connected in the same
order no matter the order of loading the
modules. That is required for LYB hashes to
work as they should.
diff --git a/src/tree_schema_compile.c b/src/tree_schema_compile.c
index 41871e3..d62473b 100644
--- a/src/tree_schema_compile.c
+++ b/src/tree_schema_compile.c
@@ -4055,7 +4055,8 @@
 }
 
 /**
- * @brief Connect the node into the siblings list and check its name uniqueness.
+ * @brief Connect the node into the siblings list and check its name uniqueness. Also,
+ * keep specific order of augments targetting the same node.
  *
  * @param[in] ctx Compile context
  * @param[in] parent Parent node holding the children list, in case of node from a choice's case,
@@ -4067,7 +4068,8 @@
 static LY_ERR
 lys_compile_node_connect(struct lysc_ctx *ctx, struct lysc_node *parent, struct lysc_node *node)
 {
-    struct lysc_node **children;
+    struct lysc_node **children, *start, *end;
+    const struct lys_module *mod;
 
     if (node->nodetype == LYS_CASE) {
         children = (struct lysc_node**)&((struct lysc_node_choice*)parent)->cases;
@@ -4084,10 +4086,32 @@
              * the first child of each case must be referenced from the case node. So the node is
              * actually always already inserted in case it is the first children - so here such
              * a situation actually corresponds to the first branch */
-            /* insert at the end of the parent's children list */
-            (*children)->prev->next = node;
-            node->prev = (*children)->prev;
-            (*children)->prev = node;
+            if (((*children)->prev->module != (*children)->module) && (node->module != (*children)->module)
+                    && (strcmp((*children)->prev->module->name, node->module->name) > 0)) {
+                /* some augments are already connected and we are connecting new ones,
+                 * keep module name order and insert the node into the children list */
+                end = (*children);
+                do {
+                    end = end->prev;
+                    mod = end->module;
+                    while (end->prev->module == mod) {
+                        end = end->prev;
+                    }
+                } while ((end->prev->module != (*children)->module) && (end->prev->module != node->module)
+                        && (strcmp(mod->name, node->module->name) > 0));
+
+                /* we have the last existing node after our node, easily get the first before and connect it */
+                start = end->prev;
+                start->next = node;
+                node->next = end;
+                end->prev = node;
+                node->prev = start;
+            } else {
+                /* insert at the end of the parent's children list */
+                (*children)->prev->next = node;
+                node->prev = (*children)->prev;
+                (*children)->prev = node;
+            }
 
             /* check the name uniqueness */
             if (lys_compile_node_uniqness(ctx, *children, lysc_node_actions(parent),