RemiNV:

Observed on LuCI openwrt-19.07 branch (git-20.136.49537-fb2f363) / OpenWrt 19.07.3 r11063-85e04e9f46, on Chrome browser

Repro steps:

• Install packages map, luci-proto-ipv6
• Add interface with protocol type "MAP / LW4over6"
• Try to edit the interface options in LuCI, and click save

Expected: Changes are saved and dialog is dismissed
Actual: "Save" button gets greyed out but dialog stays there. Chrome console says:

form.js?v=git-20.136.49537-fb2f363:formatted:1399 Uncaught TypeError: elem.isChecked is not a function
at ClassConstructor.formvalue (form.js?v=git-20.136.49537-fb2f363:formatted:1399)
at ClassConstructor.parse (form.js?v=git-20.136.49537-fb2f363:formatted:1410)
at ClassConstructor.parse (form.js?v=git-20.136.49537-fb2f363:formatted:386)
at ClassConstructor.parse (form.js?v=git-20.136.49537-fb2f363:formatted:237)
at ClassConstructor.save (form.js?v=git-20.136.49537-fb2f363:formatted:242)
at ClassConstructor.handleModalSave (form.js?v=git-20.136.49537-fb2f363:formatted:1043)
at ClassConstructor.super (luci.js?v=git-20.136.49537-fb2f363:22)
at ClassConstructor.handleModalSave (form.js?v=git-20.136.49537-fb2f363:formatted:1107)
at ClassConstructor.eval (ui.js?v=git-20.136.49537-fb2f363:300)

It appears that LuCI is confused by the fact that there are two controls for the "type" option:

• The "Bridge interfaces" checkbox (actually hidden for MAP, but still there, and documented in "Options valid for all protocol types" here: https://openwrt.org/docs/guide-user/base-system/basic-networking)
• The MAP type option (MAP-E, MAP-T, LW4over6)

It does not seem correct to have "type" be both a common option for all protocols, and have a different option with the same name for MAP: this makes the configuration ambiguous (which is why LuCI gets confused). I think renaming "type" to "maptype" (for example) for MAP would be the best solution.