Fix mysqltest to automatically replace \ with / also in

$MYSQLTEST_VARDIR, for usage of vardir=e:/var<nnn> on windows


client/mysqltest.c:
  Add auto replace for $MYSQLTEST_VARDIR
  Only add strings with strlen > to patterns array - avoids
  lot of strlen calls

client/mysqltest.c

@@ -4138,8 +4138,9 @@ void init_win_path_patterns()
   /* List of string patterns to match in order to find paths */
   const char* paths[] = { "$MYSQL_TEST_DIR",
                           "$MYSQL_TMP_DIR",
-                          "./test/", 0 };
-  int num_paths= 3;
+                          "$MYSQLTEST_VARDIR",
+                          "./test/" };
+  int num_paths= sizeof(paths)/sizeof(char*),
   int i;
   char* p;
 
@@ -4159,6 +4160,13 @@ void init_win_path_patterns()
     else
       p= my_strdup(paths[i], MYF(MY_FAE));
 
+    /* Don't insert zero length strings in patterns array */
+    if (strlen(p) == 0)
+    {
+      my_free(p, MYF(0));
+      continue;
+    }
+
     if (insert_dynamic(&patterns, (gptr) &p))
       die(NullS);
 
@@ -4208,7 +4216,7 @@ void fix_win_paths(const char *val, int len)
   {
     const char** pattern= dynamic_element(&patterns, i, const char**);
     DBUG_PRINT("info", ("pattern: %s", *pattern));
-    if (strlen(*pattern) == 0) continue;
+
     /* Search for the path in string */
     while ((p= strstr(val, *pattern)))
     {