improve detection of fdopen() and strerror_r()

acinclude.m4

@@ -2620,115 +2620,6 @@ AC_DEFUN([CURL_CHECK_LOCALTIME_R],
         AC_MSG_RESULT(no))])])
 ])
 
-dnl
-dnl This function checks for strerror_r(). If it isn't found at first, it
-dnl retries with _THREAD_SAFE defined, as that is what AIX seems to require
-dnl in order to find this function.
-dnl
-dnl If the function is found, it will then proceed to check how the function
-dnl actually works: glibc-style or POSIX-style.
-dnl
-dnl glibc:
-dnl      char *strerror_r(int errnum, char *buf, size_t n);
-dnl  
-dnl  What this one does is to return the error string (no surprises there),
-dnl  but it doesn't usually copy anything into buf!  The 'buf' and 'n'
-dnl  parameters are only meant as an optional working area, in case strerror_r
-dnl  needs it.  A quick test on a few systems shows that it's generally not
-dnl  touched at all.
-dnl
-dnl POSIX:
-dnl      int strerror_r(int errnum, char *buf, size_t n);
-dnl
-AC_DEFUN([CURL_CHECK_STRERROR_R],
-[
-  AC_CHECK_FUNCS(strerror_r)
-
-  if test "x$ac_cv_func_strerror_r" = "xyes"; then
-
-    AC_MSG_CHECKING(whether strerror_r is declared)
-    AC_EGREP_CPP(strerror_r,[
-#undef _REENTRANT
-#include <string.h>],[
-      AC_MSG_RESULT(yes)],[
-      AC_MSG_RESULT(no)
-      AC_MSG_CHECKING(whether strerror_r with -D_REENTRANT is declared)
-      AC_EGREP_CPP(strerror_r,[
-#undef _REENTRANT
-#define _REENTRANT
-#include <string.h>],[
-        AC_MSG_RESULT(yes)],
-        AC_MSG_RESULT(no)
-        AC_DEFINE(HAVE_NO_STRERROR_R_DECL, 1, [we have no strerror_r() proto])
-       ) dnl with _THREAD_SAFE
-    ]) dnl plain cpp for it
-
-    dnl determine if this strerror_r() is glibc or POSIX
-    AC_MSG_CHECKING([for a glibc strerror_r API])
-    AC_TRY_RUN([
-#include <string.h>
-#include <errno.h>
-int
-main () {
-  char buffer[1024]; /* big enough to play with */
-  char *string =
-    strerror_r(EACCES, buffer, sizeof(buffer));
-    /* this should've returned a string */
-    if(!string || !string[0])
-      return 99;
-    return 0;
-}
-],
-    GLIBC_STRERROR_R="1"
-    AC_DEFINE(HAVE_GLIBC_STRERROR_R, 1, [we have a glibc-style strerror_r()])
-    AC_MSG_RESULT([yes]),
-    AC_MSG_RESULT([no]),
-
-    dnl Use an inferior method of strerror_r detection while cross-compiling
-    AC_EGREP_CPP(yes, [
-#include <features.h>
-#ifdef __GLIBC__
-yes
-#endif
-], 
-      dnl looks like glibc, so assume a glibc-style strerror_r()
-      GLIBC_STRERROR_R="1"
-      AC_DEFINE(HAVE_GLIBC_STRERROR_R, 1, [we have a glibc-style strerror_r()])
-      AC_MSG_RESULT([yes]),
-      AC_MSG_NOTICE([cannot determine strerror_r() style: edit lib/config.h manually!])
-    ) dnl while cross-compiling
-    )
-
-    if test -z "$GLIBC_STRERROR_R"; then
-
-      AC_MSG_CHECKING([for a POSIX strerror_r API])
-      AC_TRY_RUN([
-#include <string.h>
-#include <errno.h>
-int
-main () {
-  char buffer[1024]; /* big enough to play with */
-  int error =
-    strerror_r(EACCES, buffer, sizeof(buffer));
-    /* This should've returned zero, and written an error string in the
-       buffer.*/
-    if(!buffer[0] || error)
-      return 99;
-    return 0;
-}
-],
-      AC_DEFINE(HAVE_POSIX_STRERROR_R, 1, [we have a POSIX-style strerror_r()])
-      AC_MSG_RESULT([yes]),
-      AC_MSG_RESULT([no]) ,
-      dnl cross-compiling!
-      AC_MSG_NOTICE([cannot determine strerror_r() style: edit lib/config.h manually!])
-    )
-
-    fi dnl if not using glibc API
-
-  fi dnl we have a strerror_r
-
-])
 
 AC_DEFUN([CURL_CHECK_INET_NTOA_R],
 [