* luci/libs: properly handle overflows in luci.ip.add()

diff --git a/libs/core/luasrc/ip.lua b/libs/core/luasrc/ip.lua
index 2fe71297d9bcc6c5acc17f040faa95e2bbff28c0..761a7811005288c56c4437496fbc0f63eb877349 100644 (file)
--- a/libs/core/luasrc/ip.lua
+++ b/libs/core/luasrc/ip.lua
@@ -382,8 +382,10 @@ function cidr.add( self, amount )
                local add = ( #shorts > 0 ) and table.remove( shorts, #shorts ) or 0
                if ( data[pos] + add ) > 0xFFFF then
                        data[pos] = ( data[pos] + add ) % 0xFFFF
-                       if pos > 2 then
+                       if pos > 1 then
                                data[pos-1] = data[pos-1] + ( add - data[pos] )
+                       else
+                               return nil
                        end
                else
                        data[pos] = data[pos] + add