MDEV-20185: Windows: Use of uninitialized value $bpath in string eq

The execution of mtr in the Windows environment fails due to
the fact that the new code from MDEV-18565 does not take into
account the need to add the ".exe" extension to the names of
executable files when searching for pre-requisites that are
needed to run SST scripts (especially when using mariabackup)
and when searching paths to some other Galera utilities.
This patch fixes this flaw.

Also adding paths to the PATH environment variable is now
done with the correct delimiter character.

mysql-test/mysql-test-run.pl

@@ -445,27 +445,37 @@ sub check_wsrep_support() {
     # ADD scripts to $PATH to that wsrep_sst_* can be found
     my ($spath) = grep { -f "$_/wsrep_sst_rsync"; } "$bindir/scripts", $path_client_bindir;
     mtr_error("No SST scripts") unless $spath;
-    $ENV{PATH}="$spath:$ENV{PATH}";
+    my $separator= (IS_WINDOWS) ? ';' : ':';
+    $ENV{PATH}="$spath$separator$ENV{PATH}";
 
     # ADD mysql client library path to path so that wsrep_notify_cmd can find mysql
     # client for loading the tables. (Don't assume each machine has mysql install)
     my ($cpath) = grep { -f "$_/mysql"; } "$bindir/scripts", $path_client_bindir;
     mtr_error("No scritps") unless $cpath;
-    $ENV{PATH}="$cpath:$ENV{PATH}" unless $cpath eq $spath;
+    $ENV{PATH}="$cpath$separator$ENV{PATH}" unless $cpath eq $spath;
 
     # ADD my_print_defaults script path to path so that SST scripts can find it
-    my ($epath) = grep { -f "$_/my_print_defaults"; } "$bindir/extra", $path_client_bindir;
+    my $my_print_defaults_exe=
+      mtr_exe_maybe_exists(
+        "$bindir/extra/my_print_defaults",
+        "$path_client_bindir/my_print_defaults");
+    my $epath= "";
+    if ($my_print_defaults_exe ne "") {
+       $epath= dirname($my_print_defaults_exe);
+    }
     mtr_error("No my_print_defaults") unless $epath;
-    $ENV{PATH}="$epath:$ENV{PATH}" unless ($epath eq $spath) or
+    $ENV{PATH}="$epath$separator$ENV{PATH}" unless ($epath eq $spath) or
                                                    ($epath eq $cpath);
 
     $extra_path= $epath;
 
+    if (!IS_WINDOWS) {
       if (which("socat")) {
         $ENV{MTR_GALERA_TFMT}="socat";
       } elsif (which("nc")) {
         $ENV{MTR_GALERA_TFMT}="nc";
       }
+    }
 
     # Check whether WSREP_PROVIDER environment variable is set.
     if (defined $ENV{'WSREP_PROVIDER'}) {
@@ -511,8 +521,9 @@ sub check_mariabackup_support() {
       "$bindir/extra/mariabackup$opt_vs_config/mariabackup",
       "$path_client_bindir/mariabackup");
   if ($mariabackup_exe ne "") {
-    my ($bpath) = grep { -f "$_/mariabackup"; } "$bindir/extra/mariabackup$opt_vs_config", $path_client_bindir;
-    $ENV{PATH}="$bpath:$ENV{PATH}" unless $bpath eq $extra_path;
+    my $bpath= dirname($mariabackup_exe);
+    my $separator= (IS_WINDOWS) ? ';' : ':';
+    $ENV{PATH}="$bpath$separator$ENV{PATH}" unless $bpath eq $extra_path;
 
     $mariabackup_path= $bpath;
 

mysql-test/suite.pm

@@ -54,11 +54,11 @@ sub skip_combinations {
   $skip{'include/have_mariabackup.inc'} = 'Need mariabackup'
             unless ::have_mariabackup();
 
-  $skip{'include/have_mariabackup.inc'} = 'Need ss'
-            unless ::which("ss");
+  $skip{'include/have_mariabackup.inc'} = 'Need socket statistics utility'
+            unless IS_WINDOWS || ::which("ss");
 
   $skip{'include/have_mariabackup.inc'} = 'Need socat or nc'
-            unless $ENV{MTR_GALERA_TFMT};
+            unless IS_WINDOWS || $ENV{MTR_GALERA_TFMT};
 
   $skip{'include/have_garbd.inc'} = 'Need garbd'
             unless ::have_garbd();