Make copy_up_file_and_fill() safe for disk full

Fixed use-copy option to mysql-test-run

mysql-test/mysql-test-run.pl:
  Fixed use-copy and added comment
sql/log.cc:
  Make copy_up_file_and_fill() safe for disk full

mysql-test/mysql-test-run.pl

@@ -2686,7 +2686,7 @@ sub setup_vardir() {
   {
     $plugindir="$opt_vardir/plugins";
     mkpath($plugindir);
-    if (IS_WINDOWS && !$opt_embedded_server || $opt_use_copy)
+    if (IS_WINDOWS && !$opt_embedded_server)
     {
       for (<$bindir/storage/*$opt_vs_config/*.dll>,
            <$bindir/plugin/*$opt_vs_config/*.dll>,
@@ -2708,7 +2708,14 @@ sub setup_vardir() {
            <$bindir/sql/*.so>)
       {
         my $pname=basename($_);
+        if ($opt_use_copy)
+        {
+          copy rel2abs($_), "$plugindir/$pname";
+        }
+        else
+        {
           symlink rel2abs($_), "$plugindir/$pname";
+        }
         set_plugin_var($pname);
       }
     }
@@ -6416,6 +6423,9 @@ Options to control what test suites or cases to run
   skip-test-list=FILE   Skip the tests listed in FILE. Each line in the file
                         is an entry and should be formatted as: 
                         <TESTNAME> : <COMMENT>
+  use-copy              Copy plugins instead of symlinking them. This is
+                        only useful when running on a system that doesn't
+                        support symlinks.
 
 Options that specify ports
 

sql/log.cc

@@ -3590,7 +3590,8 @@ static bool copy_up_file_and_fill(IO_CACHE *index_file, my_off_t offset)
     if (!bytes_read)
       break;					// end of file
     mysql_file_seek(file, offset-init_offset, MY_SEEK_SET, MYF(0));
-    if (mysql_file_write(file, io_buf, bytes_read, MYF(MY_WME | MY_NABP)))
+    if (mysql_file_write(file, io_buf, bytes_read,
+                         MYF(MY_WME | MY_NABP | MY_WAIT_IF_FULL)))
       goto err;
   }
   /* The following will either truncate the file or fill the end with \n' */