Description of problem:
when tried to fix bug 1037380 ,got following compilation error
------------------------------------------------------------------------------
gcc  -I. -I. -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches  -m64 -mtune=generic -I./libwc   -DHAVE_CONFIG_H -DAUXBIN_DIR=\"/usr/libexec/w3m\" -DCGIBIN_DIR=\"/usr/libexec/w3m/cgi-bin\" -DHELP_DIR=\"/usr/share/w3m\" -DETC_DIR=\"/etc\" -DCONF_DIR=\"/etc/w3m\" -DRC_DIR=\"~/.w3m\" -DLOCALEDIR=\"/usr/share/locale\"   -c -o frame.o frame.c
etc.c:638:8: error: conflicting types for 'sys_errlist'
 char **sys_errlist;
        ^
In file included from /usr/include/stdio.h:853:0,
                 from fm.h:18,
                 from etc.c:2:
/usr/include/bits/sys_errlist.h:27:26: note: previous declaration of 'sys_errlist' was here
 extern const char *const sys_errlist[];
                          ^
------------------------------------------------------------------------------

Version-Release number of selected component (if applicable):
w3m-0.5.3-13.fc20.x86_64

How reproducible:
always

Steps to Reproduce:
1. enable "-Werror=format-security" flag
2. Fix the API where format specifier is needed
3. still it failed to compile with above error

Actual results:
does not compile

Expected results:
should compile

Additional info:
I found the only way to fix is remove code that checks if sys_errlist variable is available or not on your system. We can't patch configure.ac as it needs to use autoreconf which fails for this very old source code. So better if we have working package by removing related code that adds function prepare_sys_errlist() code then lets remove it by patch.