v4: Check if handle is active when calling prepare

.gitignore

@@ -13,3 +13,4 @@ MYMETA.*
 *.old
 INSTALL.html
 /DBD-mysql-*
+socket.o

dbdimp.c

@@ -2977,6 +2977,11 @@ dbd_st_prepare(
   D_imp_xxh(sth);
   D_imp_dbh_from_sth;
 
+  if (!DBIc_ACTIVE(imp_dbh)) {
+    do_error(sth, JW_ERR_NOT_ACTIVE, "Statement not active" ,NULL);
+    return FALSE;
+  }
+
   if (DBIc_TRACE_LEVEL(imp_xxh) >= 2)
     PerlIO_printf(DBIc_LOGPIO(imp_xxh),
                  "\t-> dbd_st_prepare MYSQL_VERSION_ID %d, SQL statement: %s\n",

t/gh352.t

@@ -0,0 +1,29 @@
+use strict;
+use warnings;
+
+use Test::More;
+use DBI;
+use lib 't', '.';
+require 'lib.pl';
+
+use vars qw($test_dsn $test_user $test_password);
+
+my $dbh;
+eval {$dbh= DBI->connect($test_dsn, $test_user, $test_password,
+                      { RaiseError => 1, PrintError => 1, AutoCommit => 0 });};
+
+if ($@) {
+  diag $@;
+  plan skip_all => "no database connection";
+}
+plan tests => 2;
+
+# https://github.com/perl5-dbi/DBD-mysql/issues/352
+# Calling prepare on a disconnected handle causes the call to mysql_real_escape_string to segfault
+
+my $sth;
+ok $dbh->disconnect;
+my $result = eval {
+  $dbh->prepare('SELECT ?');
+};
+ok !$result