From ca75b62d5a44a1a44f9b68e8ab245d6e8fd84d6f Mon Sep 17 00:00:00 2001
From: "sergefp@mysql.com" <>
Date: Wed, 7 Apr 2004 12:58:28 +0400
Subject: [PATCH] Correct handling of parameter variables with NULL values in
 PREPARE queries

---
 mysql-test/r/ps.result | 9 +++++++++
 mysql-test/t/ps.test   | 4 ++++
 sql/sql_prepare.cc     | 6 ++++--
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/mysql-test/r/ps.result b/mysql-test/r/ps.result
index 234c4af56f4..14af3c32292 100644
--- a/mysql-test/r/ps.result
+++ b/mysql-test/r/ps.result
@@ -66,6 +66,7 @@ NULL
 NULL
 NULL
 NULL
+set @nullvar=1;
 set @nullvar=NULL;
 execute stmt5 using @nullvar;
 ? + a
@@ -74,4 +75,12 @@ NULL
 NULL
 NULL
 NULL
+set @nullvar2=NULL;
+execute stmt5 using @nullvar2;
+? + a
+NULL
+NULL
+NULL
+NULL
+NULL
 drop table t1;
diff --git a/mysql-test/t/ps.test b/mysql-test/t/ps.test
index a97de1a0de7..ab698174161 100644
--- a/mysql-test/t/ps.test
+++ b/mysql-test/t/ps.test
@@ -68,8 +68,12 @@ execute stmt5 using @a;
 
 execute stmt5 using @no_such_var;
 
+set @nullvar=1;
 set @nullvar=NULL;
 execute stmt5 using @nullvar;
 
+set @nullvar2=NULL;
+execute stmt5 using @nullvar2;
+
 drop table t1;
 
diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc
index 08691f67aa1..d9d19647c8c 100644
--- a/sql/sql_prepare.cc
+++ b/sql/sql_prepare.cc
@@ -661,7 +661,8 @@ static bool insert_params_from_vars(Prepared_statement *stmt,
     varname= var_it++;
     if ((entry= (user_var_entry*)hash_search(&stmt->thd->user_vars, 
                                              (byte*) varname->str,
-                                             varname->length)))
+                                             varname->length))
+        && entry->value)
     {
       param->item_result_type= entry->type;
       switch (entry->type)
@@ -710,7 +711,8 @@ static bool insert_params_from_vars_with_log(Prepared_statement *stmt,
     varname= var_it++;
     if ((entry= (user_var_entry*)hash_search(&stmt->thd->user_vars, 
                                              (byte*) varname->str,
-                                             varname->length)))
+                                             varname->length))
+        && entry->value)
     {
       param->item_result_type= entry->type;
       switch (entry->type)