A fix and a test case for Bug#12243 "MySQL Server crashes with 2

cursors (+ commit)" and Bug#11832 "Server crash with InnoDB + Cursors"
See comments to the changed files.

innobase/include/read0read.h

@@ -136,6 +136,9 @@ struct cursor_view_struct{
 				/* Memory heap for the cursor view */
 	read_view_t*	read_view;	
 				/* Consistent read view of the cursor*/
+	ulint		n_mysql_tables_in_use;
+                                /* number of Innobase tables used in the
+				  processing of this cursor */
 };
 
 #ifndef UNIV_NONINL

innobase/read/read0read.c

@@ -286,6 +286,11 @@ read_cursor_view_create_for_mysql(
 	curview = (cursor_view_t*) mem_heap_alloc(heap, sizeof(cursor_view_t));
 	curview->heap = heap;
 
+        /* Drop cursor tables from consideration when evaluating the need of
+          auto-commit */
+	curview->n_mysql_tables_in_use = cr_trx->n_mysql_tables_in_use;
+	cr_trx->n_mysql_tables_in_use = 0;
+
 	mutex_enter(&kernel_mutex);
 
 	curview->read_view = read_view_create_low(
@@ -360,6 +365,10 @@ read_cursor_view_close_for_mysql(
 	ut_a(curview->read_view); 
 	ut_a(curview->heap);
 
+        /* Add cursor's tables to the global count of active tables that
+          belong to this transaction */
+	trx->n_mysql_tables_in_use += curview->n_mysql_tables_in_use;
+
 	mutex_enter(&kernel_mutex);
 
 	read_view_close(curview->read_view);

innobase/row/row0sel.c

@@ -3101,12 +3101,6 @@ row_search_for_mysql(
 "InnoDB: how you can resolve the problem.\n",
 				prebuilt->table->name);
 
-		/* Restore a global read view back to a transaction. This 
-		forces MySQL always to set a cursor view before fetch from
-		a cursor. */
-
-		trx->read_view = trx->global_read_view;
-
 		return(DB_ERROR);
 	}
 
@@ -4098,12 +4092,6 @@ row_search_for_mysql(
 	}
 
 func_exit:
-	/* Restore a global read view back to a transaction. This 
-	forces MySQL always to set a cursor view before fetch from
-	a cursor. */
-
-	trx->read_view = trx->global_read_view;
-
 	trx->op_info = "";
 	if (UNIV_LIKELY_NULL(heap)) {
 		mem_heap_free(heap);

sql/ha_innodb.cc

@@ -2146,6 +2146,15 @@ innobase_close_connection(
 
 	ut_a(trx);
 
+        if (trx->active_trans == 0
+	    && trx->conc_state != TRX_NOT_STARTED) {
+	    
+	        fprintf(stderr,
+"InnoDB: Error: trx->active_trans == 0\n"
+"InnoDB: but trx->conc_state != TRX_NOT_STARTED\n");
+	}
+
+
 	if (trx->conc_state != TRX_NOT_STARTED &&
             global_system_variables.log_warnings)
           sql_print_warning("MySQL is closing a connection that has an active "

tests/mysql_client_test.c

@@ -14179,6 +14179,66 @@ static void test_bug11901()
   myquery(rc);
 }
 
+/* Bug#12243: multiple cursors, crash in a fetch after commit. */
+
+static void test_bug12243()
+{
+  MYSQL_STMT *stmt1, *stmt2;
+  int rc;
+  const char *stmt_text;
+  ulong type;
+
+  myheader("test_bug12243");
+
+  if (! have_innodb)
+  {
+    if (!opt_silent)
+      printf("This test requires InnoDB.\n");
+    return;
+  }
+
+  /* create tables */
+  mysql_query(mysql, "drop table if exists t1");
+  mysql_query(mysql, "create table t1 (a int) engine=InnoDB");
+  rc= mysql_query(mysql, "insert into t1 (a) values (1), (2)");
+  myquery(rc);
+  mysql_autocommit(mysql, FALSE);
+  /* create statement */
+  stmt1= mysql_stmt_init(mysql);
+  stmt2= mysql_stmt_init(mysql);
+  type= (ulong) CURSOR_TYPE_READ_ONLY;
+  mysql_stmt_attr_set(stmt1, STMT_ATTR_CURSOR_TYPE, (const void*) &type);
+  mysql_stmt_attr_set(stmt2, STMT_ATTR_CURSOR_TYPE, (const void*) &type);
+
+  stmt_text= "select a from t1";
+
+  rc= mysql_stmt_prepare(stmt1, stmt_text, strlen(stmt_text));
+  check_execute(stmt1, rc);
+  rc= mysql_stmt_execute(stmt1);
+  check_execute(stmt1, rc);
+  rc= mysql_stmt_fetch(stmt1);
+  check_execute(stmt1, rc);
+
+  rc= mysql_stmt_prepare(stmt2, stmt_text, strlen(stmt_text));
+  check_execute(stmt2, rc);
+  rc= mysql_stmt_execute(stmt2);
+  check_execute(stmt2, rc);
+  rc= mysql_stmt_fetch(stmt2);
+  check_execute(stmt2, rc);
+
+  rc= mysql_stmt_close(stmt1);
+  check_execute(stmt1, rc);
+  rc= mysql_commit(mysql);
+  myquery(rc);
+  rc= mysql_stmt_fetch(stmt2);
+  check_execute(stmt2, rc);
+
+  mysql_stmt_close(stmt2);
+  rc= mysql_query(mysql, "drop table t1");
+  myquery(rc);
+  mysql_autocommit(mysql, TRUE);                /* restore default */
+}
+
 /*
   Read and parse arguments and MySQL options from my.cnf
 */
@@ -14427,6 +14487,7 @@ static struct my_tests_st my_tests[]= {
   { "test_bug12001", test_bug12001 },
   { "test_bug11909", test_bug11909 },
   { "test_bug11901", test_bug11901 },
+  { "test_bug12243", test_bug12243 },
   { 0, 0 }
 };