Use system copy of cbrt() if available.

Also move the replacement inline into miarc.c, since that's the only user.

configure.ac

@@ -182,6 +182,7 @@ AC_CHECK_FUNC([mmap], AC_DEFINE(HAS_MMAP, 1, [Have the `mmap' function.]))
 
 dnl Find the math libary
 AC_CHECK_LIB(m, sqrt)
+AC_CHECK_LIB(m, cbrt, AC_DEFINE(HAVE_CBRT, 1, [Have the 'cbrt' function]))
 
 AC_CHECK_HEADERS([ndbm.h dbm.h rpcsvc/dbm.h])
 

include/dix-config.h.in

@@ -102,6 +102,9 @@
 /* Define to 1 if you have the <byteswap.h> header file. */
 #undef HAVE_BYTESWAP_H
 
+/* Define to 1 if you have cbrt */
+#undef HAVE_CBRT
+
 /* Define to 1 if you have the <dbm.h> header file. */
 #undef HAVE_DBM_H
 

mi/Makefile.am

@@ -9,7 +9,6 @@ endif
 AM_CFLAGS = $(DIX_CFLAGS)
 
 libmi_la_SOURCES = 	\
-	cbrt.c		\
 	mi.h		\
 	miarc.c		\
 	mibank.c	\

mi/cbrt.c

@@ -1,46 +0,0 @@
-/*
-
-Copyright 1990, 1998  The Open Group
-
-Permission to use, copy, modify, distribute, and sell this software and its
-documentation for any purpose is hereby granted without fee, provided that
-the above copyright notice appear in all copies and that both that
-copyright notice and this permission notice appear in supporting
-documentation.
-
-The above copyright notice and this permission notice shall be included
-in all copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
-OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
-IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
-OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
-ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
-OTHER DEALINGS IN THE SOFTWARE.
-
-Except as contained in this notice, the name of The Open Group shall
-not be used in advertising or otherwise to promote the sale, use or
-other dealings in this Software without prior written authorization
-from The Open Group.
-
-*/
-
-/* simple cbrt, in case your math library doesn't have a good one */
-
-/*
- * Would normally include <math.h> for this, but for the sake of compiler
- * warnings, we don't want to get duplicate declarations for cbrt().
- */
-
-double pow(double, double);
-double cbrt(double);
-
-double
-cbrt(double x)
-{
-    if (x > 0.0)
-	return pow(x, 1.0/3.0);
-    else
-	return -pow(-x, 1.0/3.0);
-}

mi/miarc.c

@@ -51,14 +51,7 @@ SOFTWARE.
 #include <dix-config.h>
 #endif
 
-#if defined(_XOPEN_SOURCE) || defined(__QNXNTO__) \
-	|| (defined(sun) && defined(__SVR4))
 #include <math.h>
-#else
-#define _XOPEN_SOURCE	/* to get prototype for hypot on some systems */
-#include <math.h>
-#undef _XOPEN_SOURCE
-#endif
 #include <X11/X.h>
 #include <X11/Xprotostr.h>
 #include "misc.h"
@@ -75,7 +68,17 @@ static double miDsin(double a);
 static double miDcos(double a);
 static double miDasin(double v);
 static double miDatan2(double dy, double dx);
-double	cbrt(double);
+
+#ifndef HAVE_CBRT
+static double
+cbrt(double x)
+{
+    if (x > 0.0)
+	return pow(x, 1.0/3.0);
+    else
+	return -pow(-x, 1.0/3.0);
+}
+#endif
 
 /*
  * some interesting sematic interpretation of the protocol: