[issue8211] configure: ignore AC_PROG_CC hardcoded CFLAGS

Only override the AC_PROG_CC determined CFLAGS if they were set by the user.
This restores the default behavior in the common case of not having CFLAGS
defined when running configure.

configure

 #! /bin/sh
-# From configure.in Revision: 80574 .
+# From configure.in Revision: 80647 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.61 for python 2.7.
 #
@@ -2407,7 +2407,9 @@ echo "$as_me: error: cached CC is different -- throw away $cache_file
    { (exit 1); exit 1; }; }
 fi
 
-save_CFLAGS=$CFLAGS
+# If the user set CFLAGS, use this instead of the automatically
+# determined setting
+preset_cflags="$CFLAGS"
 ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'
 ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -3327,7 +3329,10 @@ ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
 ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
 ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
-CFLAGS=$save_CFLAGS
+if test ! -z "$preset_cflags"
+then
+	CFLAGS=$preset_cflags
+fi
 
 
 
@@ -3938,7 +3943,7 @@ else
   { echo "$as_me:$LINENO: result: no" >&5
 echo "${ECHO_T}no" >&6; }
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 
 
@@ -5510,7 +5515,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 else
   ac_cv_header_stdc=no
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 fi
 
@@ -5531,7 +5536,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 else
   ac_cv_header_stdc=no
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 fi
 
@@ -6631,7 +6636,7 @@ _ACEOF
 
 
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 { echo "$as_me:$LINENO: result: $was_it_defined" >&5
 echo "${ECHO_T}$was_it_defined" >&6; }
@@ -7168,7 +7173,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 else
   ac_cv_type_uid_t=no
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 fi
 { echo "$as_me:$LINENO: result: $ac_cv_type_uid_t" >&5
@@ -15991,7 +15996,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 else
   unistd_defines_pthreads=no
 fi
-rm -f -r conftest*
+rm -f conftest*
 
     { echo "$as_me:$LINENO: result: $unistd_defines_pthreads" >&5
 echo "${ECHO_T}$unistd_defines_pthreads" >&6; }
@@ -17605,7 +17610,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
   $EGREP "yes" >/dev/null 2>&1; then
   ipv6type=$i
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 			;;
 		kame)
@@ -17628,7 +17633,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 				ipv6libdir=/usr/local/v6/lib
 				ipv6trylibc=yes
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 			;;
 		linux-glibc)
@@ -17649,7 +17654,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
   ipv6type=$i;
 				ipv6trylibc=yes
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 			;;
 		linux-inet6)
@@ -17687,7 +17692,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 				ipv6lib=inet6;
 				ipv6libdir=/usr/local/v6/lib
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 			;;
 		v6d)
@@ -17710,7 +17715,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 				ipv6libdir=/usr/local/v6/lib;
 				BASECFLAGS="-I/usr/local/v6/include $BASECFLAGS"
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 			;;
 		zeta)
@@ -17732,7 +17737,7 @@ if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
 				ipv6lib=inet6;
 				ipv6libdir=/usr/local/v6/lib
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 			;;
 		esac
@@ -26278,7 +26283,7 @@ cat >>confdefs.h <<\_ACEOF
 _ACEOF
 
 fi
-rm -f -r conftest*
+rm -f conftest*
 
   cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
@@ -26297,7 +26302,7 @@ cat >>confdefs.h <<\_ACEOF
 _ACEOF
 
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 fi
 
@@ -26567,7 +26572,7 @@ cat >>confdefs.h <<\_ACEOF
 _ACEOF
 
 fi
-rm -f -r conftest*
+rm -f conftest*
 
 fi
 

configure.in

@@ -531,9 +531,14 @@ then
 (it is also a good idea to do 'make clean' before compiling)])
 fi
 
-save_CFLAGS=$CFLAGS
+# If the user set CFLAGS, use this instead of the automatically
+# determined setting
+preset_cflags="$CFLAGS"
 AC_PROG_CC
-CFLAGS=$save_CFLAGS
+if test ! -z "$preset_cflags"
+then
+	CFLAGS=$preset_cflags
+fi
 
 AC_SUBST(CXX)
 AC_SUBST(MAINCC)