Build error while compiling with LWIP2 with IPv6

[jeffreykog]

Basic Infos

• This issue complies with the issue POLICY doc.
• I have read the documentation at readthedocs and the issue is not addressed there.
• I have tested that the issue is present in current master branch (aka latest git).
• I have searched the issue tracker for a similar issue.
• [N/A] If there is a stack dump, I have decoded it.
• I have filled out all fields below.

Platform

• Hardware: ESP-12
• Core Version: Master (8049543) and 2.5.0-beta2
• Development Env: Arduino IDE
• Operating System: Ubuntu

Settings in IDE

• Module: Adafruit Feather HUZZAH ESP8266. Same with Generic ESP8266 module
• Flash Mode: ?? No idea where to find this. If needed, please let me know
• Flash Size: 4MB
• lwip Variant: v2 IPv6 Lower Memory && v2 IPv6 Higher Bandwidth
• Reset Method: ?? No idea where to find this. If needed, please let me know
• Flash Frequency: 40MHz
• CPU Frequency: 80MHz
• Upload Using: SERIAL
• Upload Speed: 115200

Problem Description

When building the provided IPv6 example in this repo for LWip 2.0 with IPv6 support, some build errors arrise. From the source code i could not find a direct cause, so i opened it here for someone to look at. Should be reproducable with newest arduino IDE (1.8.8) and master or 2.5.0-beta2 from this repo.

MCVE Sketch

Sketch: Provided ESP6266WiFi/IPv6/IPv6.ino example in this repo.

Debug Messages

In file included from /home/jk-5/.arduino15/packages/esp8266/hardware/esp8266/2.5.0-beta2/libraries/ESP8266WiFi/examples/IPv6/IPv6.ino:22:0:
/home/jk-5/.arduino15/packages/esp8266/hardware/esp8266/2.5.0-beta2/cores/esp8266/AddrList.h: In member function 'IPAddress esp8266::AddressListImplementation::netifWrapper::addr() const':
/home/jk-5/.arduino15/packages/esp8266/hardware/esp8266/2.5.0-beta2/cores/esp8266/AddrList.h:113:61: error: conversion from 'const ip_addr_t* {aka const ip_addr*}' to 'IPAddress' is ambiguous
     IPAddress addr () const         { return ipFromNetifNum(); }
                                                             ^
/home/jk-5/.arduino15/packages/esp8266/hardware/esp8266/2.5.0-beta2/cores/esp8266/AddrList.h:113:61: note: candidates are:
In file included from /home/jk-5/.arduino15/packages/esp8266/hardware/esp8266/2.5.0-beta2/libraries/ESP8266WiFi/src/ESP8266WiFi.h:31:0,
                 from /home/jk-5/.arduino15/packages/esp8266/hardware/esp8266/2.5.0-beta2/libraries/ESP8266WiFi/examples/IPv6/IPv6.ino:19:
/home/jk-5/.arduino15/packages/esp8266/hardware/esp8266/2.5.0-beta2/cores/esp8266/IPAddress.h:79:9: note: IPAddress::IPAddress(int) <near match>
         IPAddress(int address) { ctor32(address); }
         ^
/home/jk-5/.arduino15/packages/esp8266/hardware/esp8266/2.5.0-beta2/cores/esp8266/IPAddress.h:79:9: note:   no known conversion for argument 1 from 'const ip_addr_t* {aka const ip_addr*}' to 'int'
/home/jk-5/.arduino15/packages/esp8266/hardware/esp8266/2.5.0-beta2/cores/esp8266/IPAddress.h:78:9: note: IPAddress::IPAddress(u32_t) <near match>
         IPAddress(u32_t address) { ctor32(address); }
         ^
/home/jk-5/.arduino15/packages/esp8266/hardware/esp8266/2.5.0-beta2/cores/esp8266/IPAddress.h:78:9: note:   no known conversion for argument 1 from 'const ip_addr_t* {aka const ip_addr*}' to 'u32_t {aka long unsigned int}'
/home/jk-5/.arduino15/packages/esp8266/hardware/esp8266/2.5.0-beta2/cores/esp8266/IPAddress.h:77:9: note: IPAddress::IPAddress(uint32_t) <near match>
         IPAddress(uint32_t address) { ctor32(address); }
         ^
/home/jk-5/.arduino15/packages/esp8266/hardware/esp8266/2.5.0-beta2/cores/esp8266/IPAddress.h:77:9: note:   no known conversion for argument 1 from 'const ip_addr_t* {aka const ip_addr*}' to 'uint32_t {aka unsigned int}'
exit status 1
Error compiling for board Adafruit Feather HUZZAH ESP8266.

[jeffreykog]

Tested it and confirmed to be fixed in #5551. Closing this. Thanks for the fix