Bug#43005 main.init_connect fails on Windows due to wrong quoting of args

- The arguments are properly quoted when mtr.pl calls my_safe_process but
  unfortunately the all off when running with active state perl and stays
  in cygwin perl.
- Extend the patch to only quote args that are not already quoted
This a redo of previous commit, will be included in next push

mysql-test/lib/My/SafeProcess/safe_process_win.cc

@@ -186,14 +186,20 @@ int main(int argc, const char** argv )
         die("No real args -> nothing to do");
       /* Copy the remaining args to child_arg */
       for (int j= i+1; j < argc; j++) {
-	if (strchr (argv[j], ' ')) {
-	  /* Protect with "" if this arg contains a space */
-	  to+= _snprintf(to, child_args + sizeof(child_args) - to,
-                         "\"%s\" ", argv[j]);
-	} else {
-	  to+= _snprintf(to, child_args + sizeof(child_args) - to,
-	                 "%s ", argv[j]);
-	}
+        arg= argv[j];
+        if (strchr (arg, ' ') &&
+            arg[0] != '\"' &&
+            arg[strlen(arg)] != '\"')
+        {
+          /* Quote arg that contains spaces and are not quoted already */
+          to+= _snprintf(to, child_args + sizeof(child_args) - to,
+                         "\"%s\" ", arg);
+        }
+        else
+        {
+          to+= _snprintf(to, child_args + sizeof(child_args) - to,
+          "%s ", arg);
+        }
       }
       break;
     } else {