awful.mouse.move: Fix snapping support

lib/awful/mouse/init.lua

@@ -84,7 +84,11 @@ function mouse.client.move(c, snap, finished_cb) --luacheck: no unused args
         y = geo.y - coords.y,
     }
 
-    mouse.resize(c, "mouse.move", {placement=aplace.under_mouse, offset=offset})
+    mouse.resize(c, "mouse.move", {
+        placement = aplace.under_mouse,
+        offset    = offset,
+        snap      = snap
+    })
 end
 
 mouse.client.dragtotag = { }

lib/awful/mouse/snap.lua

@@ -8,6 +8,7 @@
 ---------------------------------------------------------------------------
 
 local aclient = require("awful.client")
+local resize  = require("awful.mouse.resize")
 
 local capi = {
     root = root,
@@ -121,5 +122,15 @@ function module.snap(c, snap, x, y, fixed_x, fixed_y)
     return geom
 end
 
+-- Enable edge snapping
+resize.add_move_callback(function(c, geo, args)
+    if args and (args.snap == nil or args.snap) then
+        local ngeo = module.snap(c, args.snap, geo.x, geo.y)
+        ngeo.x = ngeo.x + (2 * c.border_width)
+        ngeo.y = ngeo.y + (2 * c.border_width)
+        return ngeo
+    end
+end, "mouse.move")
+
 return setmetatable(module, {__call = function(_, ...) return module.snap(...) end})