Avoid use of experimental bytes_to_utf8

Not too sure about this one ... while bytes_to_utf8 is "experimental" according to perlapi, it isn't labelled as such in perlguts, which actually recommends using it for our exact scenario. bytes_to_utf8 was introduced in Perl 5.7.0, so it's been around like forever and it seems unlikely that it would suddenly vanish. And avoiding bytes_to_utf8 in the way this change does uses up more (temp) memory.

In spite of all that, using "experimental" functions seems like a bad idea to me.

newSVpvn_flags is available from Perl 5.10.1.

Makefile.PL

@@ -53,7 +53,7 @@ if ($neo_info) {
 WriteMakefile(
   NAME => 'Neo4j::Bolt',
   VERSION_FROM => 'lib/Neo4j/Bolt.pm',
-  MIN_PERL_VERSION => '5.010',
+  MIN_PERL_VERSION => '5.010001',
   CONFIGURE_REQUIRES => {
     'Alien::OpenSSL' => 0,
     'ExtUtils::MakeMaker' => '7.12',
@@ -67,7 +67,6 @@ WriteMakefile(
     'Alien::OpenSSL' => 0,
     'Neo4j::Client' => '0.46',
     'Neo4j::Types' => '1.00',
-    'parent' => 0,  # parent was first released with perl v5.10.1
     'JSON::PP' => 0,
     'URI' => 0,
     'XSLoader' => '0.14',  # XSLoader::load()

lib/Neo4j/Bolt/CTypeHandlers.xs

@@ -72,11 +72,11 @@ neo4j_value_t SVnv_to_neo4j_float (SV *sv) {
 neo4j_value_t SVpv_to_neo4j_string (SV *sv) {
   STRLEN len;
   char *k0,*k;
+  SV *sv2;
   k = SvPV(sv,len);
-  if (! SvUTF8(sv)) {
-    k0 = (char *) bytes_to_utf8((U8 *)k, &len);
-    return neo4j_ustring(k0, len);
-  }
+  // create duplicate to keep SvPVutf8 from changing the original SV
+  sv2 = newSVpvn_flags(k, len, SvFLAGS(sv) & SVf_UTF8 | SVs_TEMP);
+  k = SvPVutf8(sv2, len);
   Newx(k0,len+1,char);
   memcpy(k0,k,(size_t) len);
   *(k0+len) = 0;