A fix and a test case for Bug#11909 "mysql_stmt_attr_set

CURSOR_TYPE_READ_ONLY nested queries corrupt result"


sql/sql_prepare.cc:
  If there is a cursor, use its protocol for fetch: 
  Protocol instances have a state and thd->protocol_prep can't
  be used for multiple cursors.
sql/sql_select.cc:
  - init Cursor::protocol
sql/sql_select.h:
  - add Cursor::protocol
tests/mysql_client_test.c:
  A test case for Bug#11909 "mysql_stmt_attr_set CURSOR_TYPE_READ_ONLY
   nested queries corrupt result"

1 files changed, 120 insertions, 0 deletions

diff --git a/tests/mysql_client_test.c b/tests/mysql_client_test.c
index 53708a7a741..5e6de152f40 100644
--- a/tests/mysql_client_test.c
+++ b/tests/mysql_client_test.c
@@ -13932,6 +13932,125 @@ static void test_bug12001()
   DIE_UNLESS(res==1);
 }
 
+
+/* Bug#11909: wrong metadata if fetching from two cursors */
+
+static void test_bug11909()
+{
+  MYSQL_STMT *stmt1, *stmt2;
+  MYSQL_BIND bind[7];
+  int rc;
+  char firstname[20], midinit[20], lastname[20], workdept[20];
+  ulong firstname_len, midinit_len, lastname_len, workdept_len;
+  uint32 empno;
+  double salary;
+  float bonus;
+  const char *stmt_text;
+
+  myheader("test_bug11909");
+
+  stmt_text= "drop table if exists t1";
+  rc= mysql_real_query(mysql, stmt_text, strlen(stmt_text));
+  myquery(rc);
+
+  stmt_text= "create table t1 ("
+    "  empno int(11) not null, firstname varchar(20) not null,"
+    "  midinit varchar(20) not null, lastname varchar(20) not null,"
+    "  workdept varchar(6) not null, salary double not null,"
+    "  bonus float not null, primary key (empno)"
+    ") default charset=latin1 collate=latin1_bin";
+  rc= mysql_real_query(mysql, stmt_text, strlen(stmt_text));
+  myquery(rc);
+
+  stmt_text= "insert into t1 values "
+    "(10, 'CHRISTINE', 'I', 'HAAS',     'A00', 52750, 1000), "
+    "(20, 'MICHAEL',   'L', 'THOMPSON', 'B01', 41250, 800),"
+    "(30, 'SALLY',     'A', 'KWAN',     'C01', 38250, 800),"
+    "(50, 'JOHN',      'B', 'GEYER',    'E01', 40175, 800), "
+    "(60, 'IRVING',    'F', 'STERN',    'D11', 32250, 500)";
+  rc= mysql_real_query(mysql, stmt_text, strlen(stmt_text));
+  myquery(rc);
+
+  /* ****** Begin of trace ****** */
+
+  stmt1= open_cursor("SELECT empno, firstname, midinit, lastname,"
+                     "workdept, salary, bonus FROM t1");
+
+  bzero(bind, sizeof(bind));
+  bind[0].buffer_type= MYSQL_TYPE_LONG;
+  bind[0].buffer= (void*) &empno;
+
+  bind[1].buffer_type= MYSQL_TYPE_VAR_STRING;
+  bind[1].buffer= (void*) firstname;
+  bind[1].buffer_length= sizeof(firstname);
+  bind[1].length= &firstname_len;
+
+  bind[2].buffer_type= MYSQL_TYPE_VAR_STRING;
+  bind[2].buffer= (void*) midinit;
+  bind[2].buffer_length= sizeof(midinit);
+  bind[2].length= &midinit_len;
+
+  bind[3].buffer_type= MYSQL_TYPE_VAR_STRING;
+  bind[3].buffer= (void*) lastname;
+  bind[3].buffer_length= sizeof(lastname);
+  bind[3].length= &lastname_len;
+
+  bind[4].buffer_type= MYSQL_TYPE_VAR_STRING;
+  bind[4].buffer= (void*) workdept;
+  bind[4].buffer_length= sizeof(workdept);
+  bind[4].length= &workdept_len;
+
+  bind[5].buffer_type= MYSQL_TYPE_DOUBLE;
+  bind[5].buffer= (void*) &salary;
+
+  bind[6].buffer_type= MYSQL_TYPE_FLOAT;
+  bind[6].buffer= (void*) &bonus;
+  rc= mysql_stmt_bind_result(stmt1, bind);
+  check_execute(stmt1, rc);
+
+  rc= mysql_stmt_execute(stmt1);
+  check_execute(stmt1, rc);
+
+  rc= mysql_stmt_fetch(stmt1);
+  DIE_UNLESS(rc == 0);
+  DIE_UNLESS(empno == 10);
+  DIE_UNLESS(strcmp(firstname, "CHRISTINE") == 0);
+  DIE_UNLESS(strcmp(midinit, "I") == 0);
+  DIE_UNLESS(strcmp(lastname, "HAAS") == 0);
+  DIE_UNLESS(strcmp(workdept, "A00") == 0);
+  DIE_UNLESS(salary == (double) 52750.0);
+  DIE_UNLESS(bonus == (float) 1000.0);
+
+  stmt2= open_cursor("SELECT empno, firstname FROM t1");
+  rc= mysql_stmt_bind_result(stmt2, bind);
+  check_execute(stmt2, rc);
+
+  rc= mysql_stmt_execute(stmt2);
+  check_execute(stmt2, rc);
+
+  rc= mysql_stmt_fetch(stmt2);
+  DIE_UNLESS(rc == 0);
+
+  DIE_UNLESS(empno == 10);
+  DIE_UNLESS(strcmp(firstname, "CHRISTINE") == 0);
+
+  rc= mysql_stmt_reset(stmt2);
+  check_execute(stmt2, rc);
+
+  /* ERROR: next statement should return 0 */
+
+  rc= mysql_stmt_fetch(stmt1);
+  DIE_UNLESS(rc == 0);
+
+  mysql_stmt_close(stmt1);
+  mysql_stmt_close(stmt2);
+  rc= mysql_rollback(mysql);
+  myquery(rc);
+
+  rc= mysql_query(mysql, "drop table t1");
+  myquery(rc);
+}
+
 /*
   Read and parse arguments and MySQL options from my.cnf
 */
@@ -14178,6 +14297,7 @@ static struct my_tests_st my_tests[]= {
   { "test_bug11037", test_bug11037 },
   { "test_bug10760", test_bug10760 },
   { "test_bug12001", test_bug12001 },
+  { "test_bug11909", test_bug11909 },
   { 0, 0 }
 };