cowboy crash when the browser send if-None-Match: "i0KCY3fxWkmxwUaTq08lH...

browser firefox 26.0 for ubuntu or chrome Version 31.0.1650.63 Ubuntu 13.10 (31.0.1650.63-0ubuntu0.13.10.1~20131204.1)

error log i had: (i put some trace in cowboy)

14:28:03.925 [info] cowboy_http:entity_tag_match data <<"/xxqBN2Ay6hSGoUMrnKKu0HqnvM=">> process <0.356.0>
14:28:03.925 [error] Error in process <0.356.0> on node 'dayou@127.0.0.1' with exit value: {function_clause,[{lists,reverse,[<<28 bytes>>],[{file,"lists.erl"},{line,145}]},{cowboy_req,parse_header,4,[{file,"src/cowboy_req.erl"},{line,473}]},{cowboy_rest,if_none_match_exists,2,[{file,"src/cowboy_rest.erl"},{line,583}]},{cowboy_protocol... 

14:28:03.991 [error] Ranch listener boss_http_listener had connection process started with cowboy_protocol:start_link/4 at <0.356.0> exit with reason: {function_clause,[{lists,reverse,[<<"/xxqBN2Ay6hSGoUMrnKKu0HqnvM=">>],[{file,"lists.erl"},{line,145}]},{cowboy_req,parse_header,4,[{file,"src/cowboy_req.erl"},{line,473}]},{cowboy_rest,if_none_match_exists,2,[{file,"src/cowboy_rest.erl"},{line,583}]},{cowboy_protocol,execute,4,[{file,"src/cowboy_protocol.erl"},{line,529}]}]}

14:28:04.058 [info] rest_init_info {ok,{file_info,495,regular,read_write,{{2014,1,3},{5,55,13}},{{2014,1,2},{5,50,33}},{{2014,1,2},{5,50,33}},33188,1,2053,0,4602344,1000,1000}}
14:28:04.058 [info] {ok,{file_info,495,regular,read_write,{{2014,1,3},{5,55,13}},{{2014,1,2},{5,50,33}},{{2014,1,2},{5,50,33}},33188,1,2053,0,4602344,1000,1000}} resource_exists true
14:28:04.058 [info] cowboy_http:entity_tag_match data <<"yfkzK/n5aZUti7wW8e9eg2ttVpY=">> process <0.357.0>
14:28:04.058 [error] Error in process <0.357.0> on node 'dayou@127.0.0.1' with exit value: {function_clause,[{lists,reverse,[<<28 bytes>>],[{file,"lists.erl"},{line,145}]},{cowboy_req,parse_header,4,[{file,"src/cowboy_req.erl"},{line,473}]},{cowboy_rest,if_none_match_exists,2,[{file,"src/cowboy_rest.erl"},{line,583}]},{cowboy_protocol... 

14:28:04.125 [error] Ranch listener boss_http_listener had connection process started with cowboy_protocol:start_link/4 at <0.357.0> exit with reason: {function_clause,[{lists,reverse,[<<"yfkzK/n5aZUti7wW8e9eg2ttVpY=">>],[{file,"lists.erl"},{line,145}]},{cowboy_req,parse_header,4,[{file,"src/cowboy_req.erl"},{line,473}]},{cowboy_rest,if_none_match_exists,2,[{file,"src/cowboy_rest.erl"},{line,583}]},{cowboy_protocol,execute,4,[{file,"src/cowboy_protocol.erl"},{line,529}]}]}