BIO: Undefine UNICODE in b_addr.c to get POSIX declaration of gai_strerror()
When UNICODE is defined, Windows headers push for WCHAR implementations,
which aren't compatible with POSIX declarations.
# define _GNU_SOURCE
#endif
+/*
+ * VC configurations may define UNICODE, to indicate to the C RTL that
+ * WCHAR functions are preferred.
+ * This affects functions like gai_strerror(), which is implemented as
+ * an alias macro for gai_strerrorA() (which returns a const char *) or
+ * gai_strerrorW() (which returns a const WCHAR *). This source file
+ * assumes POSIX declarations, so prefer the non-UNICODE definitions.
+ */
+#undef UNICODE
+
#include <assert.h>
#include <string.h>
