Use (from Matt Hall) AC_CANONICAL_HOST rather than AC_MINGW32 to detect the latter.

Try different way of detecting opengl libs in mingw32 case too.

src/configure.in

@@ -4,7 +4,8 @@ dnl ---------------------------------------------------------------------------
 
 AC_MSG_CHECKING([partiview])
 
-AC_INIT(partibrains.c)
+AC_INIT
+AC_CONFIG_SRCDIR([partibrains.c])
 
 AC_CONFIG_HEADER(config.h)
 
@@ -19,10 +20,13 @@ dnl -- checks for system services
 
 
 AC_HEADER_STDC
+AC_CHECK_FUNCS(strchr memcpy snprintf strcasecmp rint sqrtf)
+AC_CHECK_HEADERS(malloc.h)
 AC_FUNC_ALLOCA
 
 AC_PROG_CC
 AC_PROG_CPP
+AC_PROG_CC
 AC_PROG_CXX
 AC_PROG_INSTALL
 AC_PROG_MAKE_SET
@@ -34,8 +38,8 @@ AC_ARG_PROGRAM
 
 AC_ARG_ENABLE(debug, [  --enable-debug          compile for debugging], ok=$enableval, ok=no)
 if test "$ok" = "yes"; then
-        CFLAGS="-g"
-        LDFLAGS="-g"
+        CFLAGS="${CFLAGS} -g"
+        LDFLAGS="${LDFLAGS} -g"
         # should we define DEBUG too?
 fi
 
@@ -47,9 +51,14 @@ dnl AC_ARG_WITH(cave, [  --enable-cave      compile for CAVE], with_cave=$enable
 
 dnl ---------------------------------------------------------------------
 dnl             Building on Windows under MINGW32?  Used below.
-AC_MINGW32
+AC_CANONICAL_HOST()
+AC_DIAGNOSE([obsolete],[AC_MINGW32 is obsolete: use AC_CANONICAL_HOST and $host_os])case $host_os in
+  *mingw32* ) MINGW32=yes;;
+          * ) MINGW32=;;
+esac
+
 
-if test "yes" = "$MINGW32"; then
+if test -n "$MINGW32"; then
 	PV_FLAGS="-D_WIN32"
 	PORT_OBJS="winjunk.o"
 else
@@ -133,17 +142,16 @@ if test "$with_mesa" != "yes"; then
 fi
 if test -z "$GLLIBS" && test "no" != "$with_mesa"; then
         AC_CHECK_LIB(MesaGL, glBegin,
-            AC_CHECK_LIB(MesaGLU, gluProject, GLLIBS="-lMesaGLU -lMesaGL",
+            AC_CHECK_LIB(MesaGLU, gluProject, GLLIBS=[-lMesaGLU -lMesaGL],
                          :, -lMesaGL $XLIBS -lm), :, $XLIBS -lm)
 fi
 if test -z "$GLLIBS" && test -n "$MINGW32"; then
 	dnl Test for both -lglu32 and -lopengl32 together.
 	dnl Doesn't seem to work to use AC_CHECK_LIB(lib, func) here
-	dnl on Windows, so we use AC_HAVE_LIBRARY even though it's obsolete.
+	dnl on Windows, so we use AC_CHECK_LIB([],[main],[],[],[])ac_cv_lib_=ac_cv_lib__main  even though it's obsolete.
 	dnl Feh.
-	AC_HAVE_LIBRARY(opengl32,
-			GLLIBS="-lopengl32 -lglu32", ,
-			-lglu32 $XLIBS -lm)
+	AC_CHECK_LIB([opengl32],[main],[GLLIBS="-lopengl32 -lglu32"],[],[-lglu32 $XLIBS -lm])ac_cv_lib_opengl32=ac_cv_lib_opengl32_main
+
 fi
 if test "$with_mesa" = "yes"; then
         AC_CHECK_LIB(GL, glBegin,
@@ -242,7 +250,7 @@ AC_PROG_GCC_TRADITIONAL
 AC_FUNC_MEMCMP
 AC_FUNC_MMAP
 AC_TYPE_SIGNAL
-AC_FUNC_VFORK
+AC_FUNC_FORK([])
 AC_FUNC_VPRINTF
 
 AC_SEARCH_LIBS(sqrtf, [m], AC_DEFINE(HAVE_SQRTF))
@@ -359,7 +367,8 @@ if test -f "$NEMOBIN/cc"; then
 fi
 
 
-AC_OUTPUT(Makefile  ../cmed/Makefile)
+AC_CONFIG_FILES([Makefile  ../cmed/Makefile])
+AC_OUTPUT
 
 dnl ensure that "Makedepend" exists but don't put anything into it
 dnl and force user to "make depend" to fill it in, since we're reconfiguring.