Fixed bug #47485 - mysql_store_result returns a not NULL result set

for a prepared statement.

include/mysql.h:
  enumerator MYSQL_STATUS_STATEMENT_GET_RESULT was added
  into mysql_status enum.
include/mysql.h.pp:
  enumerator MYSQL_STATUS_STATEMENT_GET_RESULT was added
  into mysql_status enum.
libmysql/libmysql.c:
  Introduce a separate mysql state to distinguish the situation
  when we have a binary result set pending on the server from the
  situation when the result set is in text protocol.
  execute() modified: if mysql->status == MYSQL_STATUS_GET_RESULT
  before return then set it to value MYSQL_STATUS_STATEMENT_GET_RESULT.
  stmt_read_row_unbuffered() and mysql_stmt_store_result()
  were modified: added checking for mysql->status against
  MYSQL_STATUS_STATEMENT_GET_RESULT value instead of MYSQL_STATUS_GET_RESULT.
tests/mysql_client_test.c:
  added test_bug47485()

4 files changed, 110 insertions, 4 deletions

diff --git a/include/mysql.h b/include/mysql.h
index dcf3e167e6a..699bd1f1b7f 100644
--- a/include/mysql.h
+++ b/include/mysql.h
@@ -224,7 +224,8 @@ struct st_mysql_options {
 
 enum mysql_status 
 {
-  MYSQL_STATUS_READY,MYSQL_STATUS_GET_RESULT,MYSQL_STATUS_USE_RESULT
+  MYSQL_STATUS_READY, MYSQL_STATUS_GET_RESULT, MYSQL_STATUS_USE_RESULT,
+  MYSQL_STATUS_STATEMENT_GET_RESULT
 };
 
 enum mysql_protocol_type 
diff --git a/include/mysql.h.pp b/include/mysql.h.pp
index 0a397863022..ceb4b2d591c 100644
--- a/include/mysql.h.pp
+++ b/include/mysql.h.pp
@@ -293,7 +293,8 @@ struct st_mysql_options {
 };
 enum mysql_status
 {
-  MYSQL_STATUS_READY,MYSQL_STATUS_GET_RESULT,MYSQL_STATUS_USE_RESULT
+  MYSQL_STATUS_READY, MYSQL_STATUS_GET_RESULT, MYSQL_STATUS_USE_RESULT,
+  MYSQL_STATUS_STATEMENT_GET_RESULT
 };
 enum mysql_protocol_type
 {
diff --git a/libmysql/libmysql.c b/libmysql/libmysql.c
index 362ad5de6c4..8c612b6894e 100644
--- a/libmysql/libmysql.c
+++ b/libmysql/libmysql.c
@@ -2503,6 +2503,8 @@ static my_bool execute(MYSQL_STMT *stmt, char *packet, ulong length)
       set_stmt_errmsg(stmt, net);
     DBUG_RETURN(1);
   }
+  else if (mysql->status == MYSQL_STATUS_GET_RESULT)
+    stmt->mysql->status= MYSQL_STATUS_STATEMENT_GET_RESULT;
   DBUG_RETURN(0);
 }
 
@@ -2641,7 +2643,7 @@ static int stmt_read_row_unbuffered(MYSQL_STMT *stmt, unsigned char **row)
     set_stmt_error(stmt, CR_SERVER_LOST, unknown_sqlstate, NULL);
     return 1;
   }
-  if (mysql->status != MYSQL_STATUS_GET_RESULT)
+  if (mysql->status != MYSQL_STATUS_STATEMENT_GET_RESULT)
   {
     set_stmt_error(stmt, stmt->unbuffered_fetch_cancelled ?
                    CR_FETCH_CANCELED : CR_COMMANDS_OUT_OF_SYNC,
@@ -4847,7 +4849,7 @@ int STDCALL mysql_stmt_store_result(MYSQL_STMT *stmt)
       DBUG_RETURN(1);
     }
   }
-  else if (mysql->status != MYSQL_STATUS_GET_RESULT)
+  else if (mysql->status != MYSQL_STATUS_STATEMENT_GET_RESULT)
   {
     set_stmt_error(stmt, CR_COMMANDS_OUT_OF_SYNC, unknown_sqlstate, NULL);
     DBUG_RETURN(1);
diff --git a/tests/mysql_client_test.c b/tests/mysql_client_test.c
index 87c35666ac6..3bfcf3ee233 100644
--- a/tests/mysql_client_test.c
+++ b/tests/mysql_client_test.c
@@ -18297,6 +18297,107 @@ static void test_bug54041()
 }
 
 
+/**
+  Bug#47485: mysql_store_result returns a result set for a prepared statement
+*/
+static void test_bug47485()
+{
+  MYSQL_STMT   *stmt;
+  MYSQL_RES    *res;
+  MYSQL_BIND    bind[2];
+  int           rc;
+  const char*   sql_select = "SELECT 1, 'a'";
+  int           int_data;
+  char          str_data[16];
+  my_bool       is_null[2];
+  my_bool       error[2];
+  unsigned long length[2];
+
+  DBUG_ENTER("test_bug47485");
+  myheader("test_bug47485");
+
+  stmt= mysql_stmt_init(mysql);
+  check_stmt(stmt);
+  rc= mysql_stmt_prepare(stmt, sql_select, strlen(sql_select));
+  check_execute(stmt, rc);
+
+  rc= mysql_stmt_execute(stmt);
+  check_execute(stmt, rc);
+
+  res = mysql_store_result(mysql);
+  DIE_UNLESS(res == NULL);
+
+  mysql_stmt_reset(stmt);
+
+  rc= mysql_stmt_execute(stmt);
+  check_execute(stmt, rc);
+
+  res = mysql_use_result(mysql);
+  DIE_UNLESS(res == NULL);
+
+  mysql_stmt_reset(stmt);
+
+  memset(bind, 0, sizeof(bind));
+  bind[0].buffer_type= MYSQL_TYPE_LONG;
+  bind[0].buffer= (char *)&int_data;
+  bind[0].is_null= &is_null[0];
+  bind[0].length= &length[0];
+  bind[0].error= &error[0];
+
+  bind[1].buffer_type= MYSQL_TYPE_STRING;
+  bind[1].buffer= (char *)str_data;
+  bind[1].buffer_length= sizeof(str_data);
+  bind[1].is_null= &is_null[1];
+  bind[1].length= &length[1];
+  bind[1].error= &error[1];
+
+  rc= mysql_stmt_bind_result(stmt, bind);
+  check_execute(stmt, rc);
+
+  rc= mysql_stmt_execute(stmt);
+  check_execute(stmt, rc);
+
+  rc= mysql_stmt_store_result(stmt);
+  check_execute(stmt, rc);
+
+  while (!(rc= mysql_stmt_fetch(stmt)))
+    ;
+
+  DIE_UNLESS(rc == MYSQL_NO_DATA);
+
+  mysql_stmt_reset(stmt);
+
+  memset(bind, 0, sizeof(bind));
+  bind[0].buffer_type= MYSQL_TYPE_LONG;
+  bind[0].buffer= (char *)&int_data;
+  bind[0].is_null= &is_null[0];
+  bind[0].length= &length[0];
+  bind[0].error= &error[0];
+
+  bind[1].buffer_type= MYSQL_TYPE_STRING;
+  bind[1].buffer= (char *)str_data;
+  bind[1].buffer_length= sizeof(str_data);
+  bind[1].is_null= &is_null[1];
+  bind[1].length= &length[1];
+  bind[1].error= &error[1];
+
+  rc= mysql_stmt_bind_result(stmt, bind);
+  check_execute(stmt, rc);
+
+  rc= mysql_stmt_execute(stmt);
+  check_execute(stmt, rc);
+
+  while (!(rc= mysql_stmt_fetch(stmt)))
+    ;
+
+  DIE_UNLESS(rc == MYSQL_NO_DATA);
+
+  mysql_stmt_close(stmt);
+
+  DBUG_VOID_RETURN;
+}
+
+
 /*
   Read and parse arguments and MySQL options from my.cnf
 */
@@ -18622,6 +18723,7 @@ static struct my_tests_st my_tests[]= {
   { "test_bug44495", test_bug44495 },
   { "test_bug42373", test_bug42373 },
   { "test_bug54041", test_bug54041 },
+  { "test_bug47485", test_bug47485 },
   { 0, 0 }
 };