augeas back-end: order nodes according to model topology

1 files changed, 25 insertions, 6 deletions

diff --git a/acf/persistence/backends/augeas.lua b/acf/persistence/backends/augeas.lua
index 165cf8b..9d6b4cc 100644
--- a/acf/persistence/backends/augeas.lua
+++ b/acf/persistence/backends/augeas.lua
@@ -5,6 +5,7 @@ See LICENSE file for license details
 
 module(..., package.seeall)
 
+local topology = require('acf.model.root').topology
 local pth = require('acf.path')
 
 local util = require('acf.util')
@@ -97,12 +98,30 @@ function backend:set(mods)
       self.aug:rm(aug_path(path)..(delete and '' or '/*'))
 
       local apath, mvpath, index = self:find(path, type(value) ~= 'table')
+      local mpath = mvpath or apath
+
+      if not delete then
+	 if #self.aug:match(mpath) == 0 then
+
+	    local function order(path)
+	       return topology('/augeas'..path).order
+	    end
+	    local ord = order(pth.join('/', unpack(path)))
+
+	    for _, sibling in ipairs(self.aug:match(pth.parent(mpath)..'/*')) do
+	       if order(string.sub(strip_name(sibling), 7, -1)) > ord then
+		  self.aug:insert(sibling, pth.name(mpath), true)
+		  break
+	       end
+	    end
+	 end
 
-      if not delete and mvpath then
-	 local size = #self.aug:match(mvpath)
-	 while size < index do
-	    self.aug:insert(ipath(mvpath, size), pth.name(mvpath))
-	    size = size + 1
+	 if mvpath then
+	    local size = #self.aug:match(mvpath)
+	    while size < index do
+	       self.aug:insert(ipath(mvpath, size), pth.name(mvpath))
+	       size = size + 1
+	    end
 	 end
       end
 
@@ -110,7 +129,7 @@ function backend:set(mods)
       if not delete or mvpath then self.aug:set(apath, value)
       elseif apath > '/' then apath = pth.parent(apath) end
 
-      if delete or value == '' then gcpaths[mvpath or apath] = true end
+      if delete or value == '' then gcpaths[mpath] = true end
    end
 
    local function gc(path)