Increase the buffer size used for the host names in wxIPaddress.

This avoids failing to set the host name if the system /etc/hosts file has any
host names that wouldn't fit in our buffer: at least under Linux/glibc,
gethostname_r() returns error if any such names exist even if we don't ask for
them.

Closes #16641.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@78505 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -577,6 +577,10 @@ Major new features in this release
 3.0.3: (released 2015-??-??)
 ----------------------------
 
+Unix:
+
+- Fix wxIPaddress::Hostname() failing if /etc/hosts contained very long names.
+
 All (GUI):
 
 - Fix several floating point rounding bugs in wxPropertyGrid (Artur Wieczorek).

src/common/sckaddr.cpp

@@ -136,7 +136,7 @@ IMPLEMENT_DYNAMIC_CLASS(wxUNIXaddress, wxSockAddress)
         }
     };
 #else
-    typedef char wxGethostBuf[1024];
+    typedef char wxGethostBuf[4096];
 #endif
 
 #ifdef HAVE_FUNC_GETSERVBYNAME_R_4
@@ -148,7 +148,7 @@ IMPLEMENT_DYNAMIC_CLASS(wxUNIXaddress, wxSockAddress)
         }
     };
 #else
-    typedef char wxGetservBuf[1024];
+    typedef char wxGetservBuf[4096];
 #endif
 
 #if defined(wxHAS_MT_SAFE_GETBY_FUNCS) || !wxUSE_THREADS