Addresses #783

Using DB_CURRENT no longer overwrites temporary memory owned by the db handle.
Added regression test.

git-svn-id: file:///svn/tokudb@3821 c7de825b-a66e-492c-adef-691d508d4ae1

newbrt/brt.c

@@ -2832,13 +2832,17 @@ static int brt_cursor_current(BRT_CURSOR cursor, int op, DBT *outkey, DBT *outva
     if (brt_cursor_not_set(cursor))
         return EINVAL;
     if (op == DB_CURRENT) {
-        DBT newkey; toku_init_dbt(&newkey);
-        DBT newval; toku_init_dbt(&newval);
+        int r = ENOSYS;
+        DBT newkey; toku_init_dbt(&newkey); newkey.flags = DB_DBT_MALLOC;
+        DBT newval; toku_init_dbt(&newval); newval.flags = DB_DBT_MALLOC;
 
         brt_search_t search; brt_search_init(&search, brt_cursor_compare_set, BRT_SEARCH_LEFT, &cursor->key, &cursor->val, cursor->brt);
-        int r = toku_brt_search(cursor->brt, &search, &newkey, &newval, logger);
+        r = toku_brt_search(cursor->brt, &search, &newkey, &newval, logger);
         if (r != 0 || compare_kv_xy(cursor->brt, &cursor->key, &cursor->val, &newkey, &newval) != 0)
-            return DB_KEYEMPTY;
+            r = DB_KEYEMPTY;
+        dbt_cleanup(&newkey);
+        dbt_cleanup(&newval);
+        if (r!=0) return r;
     }
     return brt_cursor_copyout(cursor, outkey, outval);
 }

src/tests/test_db_current_clobbers_db.c

+/* -*- mode: C; c-basic-offset: 4 -*- */
+#ident "Copyright (c) 2007 Tokutek Inc.  All rights reserved."
+
+/* DB_CURRENT */
+#include <assert.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <db.h>
+
+#include "test.h"
+
+// ENVDIR is defined in the Makefile
+
+DB_ENV *env;
+DB *db;
+DB_TXN* null_txn = NULL;
+
+int main (int UU(argc), char UU(*argv[])) {
+    int r;
+    system("rm -rf " ENVDIR);
+    r=mkdir(ENVDIR, 0777);    CKERR(r);
+    r=db_env_create(&env, 0); CKERR(r);
+    r=env->open(env, ENVDIR, DB_PRIVATE|DB_CREATE, 0777); CKERR(r);
+    r=db_create(&db, env, 0); CKERR(r);
+    r = db->open(db, null_txn, "foo.db", "main", DB_BTREE, DB_CREATE, 0666); CKERR(r);
+    DBC *cursor;
+    r = db->cursor(db, null_txn, &cursor, 0); CKERR(r);
+    DBT key, val;
+    DBT ckey, cval;
+    int k1 = 1, v1=7;
+    enum foo { blob = 1 };
+    int k2 = 2;
+    int v2 = 8;
+    r = db->put(db, null_txn, dbt_init(&key, &k1, sizeof(k1)), dbt_init(&val, &v1, sizeof(v1)), 0);
+        CKERR(r);
+    r = db->put(db, null_txn, dbt_init(&key, &k2, sizeof(k2)), dbt_init(&val, &v2, sizeof(v2)), 0);
+        CKERR(r);
+
+    r = cursor->c_get(cursor, dbt_init(&ckey, NULL, 0), dbt_init(&cval, NULL, 0), DB_LAST); 
+        CKERR(r);
+    //Copies a static pointer into val.
+    r = db->get(db, null_txn, dbt_init(&key, &k1, sizeof(k1)), dbt_init(&val, NULL, 0), 0);
+        CKERR(r);
+    assert(val.data != &v1);
+    assert(*(int*)val.data == v1);
+
+    r = cursor->c_get(cursor, dbt_init(&ckey, NULL, 0), dbt_init(&cval, NULL, 0), DB_LAST); 
+        CKERR(r);
+
+    //Does not corrupt it.
+    assert(val.data != &v1);
+    assert(*(int*)val.data == v1);
+
+    r = cursor->c_get(cursor, &ckey, &cval, DB_CURRENT); 
+        CKERR(r);
+
+    assert(*(int*)val.data == v1); // Will bring up valgrind error.
+
+
+    r = cursor->c_del(cursor, 0); 
+        CKERR(r);
+
+    assert(*(int*)val.data == v1); // Will bring up valgrind error.
+
+    r = cursor->c_close(cursor);
+        CKERR(r);
+    r=db->close(db, 0);       CKERR(r);
+    r=env->close(env, 0);     CKERR(r);
+    return 0;
+}
+