SCRUM

Add optional second parameter to password() function. It can be used to force password()
to return fixed values. 

mysql-test/r/func_crypt.result

 select length(encrypt('foo', 'ff')) <> 0;
 length(encrypt('foo', 'ff')) <> 0
 1
-select old_password('test'),length(password("1")),length(encrypt('test')),encrypt('test','aa');
+select password("a",""), password("a",NULL), password("","a"), password(NULL,"a");
+password("a","")	password("a",NULL)	password("","a")	password(NULL,"a")
+*2517f7235d68d4ba2e5019c93420523101157a792c01	NULL		NULL
+select password("aaaaaaaaaaaaaaaa","a"), password("a","aaaaaaaaaaaaaaaa");
+password("aaaaaaaaaaaaaaaa","a")	password("a","aaaaaaaaaaaaaaaa")
+*2cd3b9a44e9a9994789a30f935c92f45a96c5472f381	*37c7c5c794ff144819f2531bf03c57772cd84e40db09
+select old_password('test'), length(password("1")), length(encrypt('test')), encrypt('test','aa');
 old_password('test')	length(password("1"))	length(encrypt('test'))	encrypt('test','aa')
 378b243e220ca493	45	13	aaqPiZY5xR5l.
+select old_password(""), old_password(NULL), password(""), password(NULL);
+old_password("")	old_password(NULL)	password("")	password(NULL)
+	NULL		NULL

mysql-test/t/func_crypt.test

 select length(encrypt('foo', 'ff')) <> 0;
 --replace_result $1$aa$4OSUA5cjdx0RUQ08opV27/ aaqPiZY5xR5l.
-select old_password('test'),length(password("1")),length(encrypt('test')),encrypt('test','aa');
+
+# Test new and old password handling functions 
+select password("a",""), password("a",NULL), password("","a"), password(NULL,"a");
+select password("aaaaaaaaaaaaaaaa","a"), password("a","aaaaaaaaaaaaaaaa");
+select old_password('test'), length(password("1")), length(encrypt('test')), encrypt('test','aa');
+select old_password(""), old_password(NULL), password(""), password(NULL);

sql/item_strfunc.cc

@@ -1271,18 +1271,52 @@ String *Item_func_trim::val_str(String *str)
   return &tmp_value;
 }
 
+/*
+ Password() function can have 2 args now. Second argument can be used
+ to make results repeatable
+*/ 
 
 String *Item_func_password::val_str(String *str)
 {
-  String *res  =args[0]->val_str(str);
+  struct rand_struct rand_st; // local structure for 2 param version
+  ulong  seed=0;              // seed to initialise random generator to
+  
   if ((null_value=args[0]->null_value))
     return 0;
-  if (res->length() == 0)
-    return &empty_string;
-  make_scrambled_password(tmp_value,res->c_ptr(),opt_old_passwords,
-                          &current_thd->rand);
-  str->set(tmp_value,get_password_length(opt_old_passwords),res->charset());
-  return str;
+    
+  if (arg_count == 1)
+  {    
+    String *res  =args[0]->val_str(str);
+    if (res->length() == 0)
+      return &empty_string;
+    make_scrambled_password(tmp_value,res->c_ptr(),opt_old_passwords,
+                            &current_thd->rand);
+    str->set(tmp_value,get_password_length(opt_old_passwords),res->charset());
+    return str;
+  }
+  else
+  {
+    /* Check second argument for NULL value. First one is already checked */
+    if ((null_value=args[1]->null_value))
+      return 0;
+    /* Generate the seed first this allows to avoid double allocation */  
+    char* seed_ptr=args[1]->val_str(str)->c_ptr();
+    while (*seed_ptr)
+    {
+      seed=seed*211+*seed_ptr; /* Use simple hashing */
+      seed_ptr++;
+    }
+    /* Use constants which allow nice random values even with small seed */
+    randominit(&rand_st,seed*111111+33333333L,seed*1111+55555555L);
+    
+    String *res  =args[0]->val_str(str);
+    if (res->length() == 0)
+      return &empty_string;
+    make_scrambled_password(tmp_value,res->c_ptr(),opt_old_passwords,
+                            &rand_st);
+    str->set(tmp_value,get_password_length(opt_old_passwords),res->charset());
+    return str;
+  }       
 }
 
 String *Item_func_old_password::val_str(String *str)

sql/item_strfunc.h

@@ -257,6 +257,7 @@ class Item_func_password :public Item_str_func
   char tmp_value[64]; /* This should be enough for new password format */
 public:
   Item_func_password(Item *a) :Item_str_func(a) {}
+  Item_func_password(Item *a, Item *b) :Item_str_func(a,b) {}
   String *val_str(String *);
   void fix_length_and_dec() { max_length = get_password_length(opt_old_passwords); }
   const char *func_name() const { return "password"; }

sql/sql_yacc.yy

@@ -2201,9 +2201,9 @@ simple_expr:
 	| NOW_SYM '(' expr ')'
 	  { $$= new Item_func_now($3); Lex->safe_to_cache_query=0;}
 	| PASSWORD '(' expr ')'
-	  {
-	    $$= new Item_func_password($3);
-	   }
+	  { $$= new Item_func_password($3); }
+        | PASSWORD '(' expr ',' expr ')'
+          { $$= new Item_func_password($3,$5); }
  	| POINTFROMTEXT '(' expr ')'
 	  { $$= new Item_func_geometry_from_text($3); }
 	| POINTFROMTEXT '(' expr ',' expr ')'