From 5c1ee7f7ba9580d5ff29e74cbb02eee335c33d94 Mon Sep 17 00:00:00 2001 From: Howard Chu Date: Mon, 22 Oct 2012 15:58:46 -0700 Subject: [PATCH] Fix MDB_PREV Could return 1 garbage record before actual data, if starting from EOF --- libraries/libmdb/mdb.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c index 89bfd71..994a5d9 100644 --- a/libraries/libmdb/mdb.c +++ b/libraries/libmdb/mdb.c @@ -3982,8 +3982,12 @@ mdb_cursor_sibling(MDB_cursor *mc, int move_right) : (mc->mc_ki[mc->mc_top] == 0)) { DPRINTF("no more keys left, moving to %s sibling", move_right ? "right" : "left"); - if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) + if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) { + /* undo cursor_pop before returning */ + mc->mc_top++; + mc->mc_snum++; return rc; + } } else { if (move_right) mc->mc_ki[mc->mc_top]++; @@ -4393,8 +4397,8 @@ mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data) } assert(IS_LEAF(mc->mc_pg[mc->mc_top])); - mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1; mc->mc_flags |= C_INITIALIZED|C_EOF; + mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1; } leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); @@ -4525,9 +4529,10 @@ fetchm: case MDB_PREV_NODUP: if (!(mc->mc_flags & C_INITIALIZED) || (mc->mc_flags & C_EOF)) { rc = mdb_cursor_last(mc, key, data); - mc->mc_flags &= ~C_EOF; - } else - rc = mdb_cursor_prev(mc, key, data, op); + mc->mc_flags |= C_INITIALIZED; + mc->mc_ki[mc->mc_top]++; + } + rc = mdb_cursor_prev(mc, key, data, op); break; case MDB_FIRST: rc = mdb_cursor_first(mc, key, data); @@ -4575,7 +4580,9 @@ mdb_cursor_touch(MDB_cursor *mc) if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) { MDB_cursor mc2; - mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL); + MDB_xcursor mcx; + mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, + mc->mc_txn->mt_dbs[MAIN_DBI].md_flags & MDB_DUPSORT ? &mcx : NULL); rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY); if (rc) return rc; -- 2.7.4