From 3f619478f796eddbba6e39502fe941b285dd97b1 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sat, 4 May 2024 20:00:34 +0200
Subject: Adding upstream version 1:10.11.6.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 storage/heap/hp_rprev.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 storage/heap/hp_rprev.c

(limited to 'storage/heap/hp_rprev.c')

diff --git a/storage/heap/hp_rprev.c b/storage/heap/hp_rprev.c
new file mode 100644
index 00000000..1d9420ba
--- /dev/null
+++ b/storage/heap/hp_rprev.c
@@ -0,0 +1,98 @@
+/* Copyright (c) 2000-2002, 2005-2007 MySQL AB
+   Use is subject to license terms
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1335  USA */
+
+#include "heapdef.h"
+
+	/* Read prev record for key */
+
+
+int heap_rprev(HP_INFO *info, uchar *record)
+{
+  uchar *pos;
+  HP_SHARE *share=info->s;
+  HP_KEYDEF *keyinfo;
+  DBUG_ENTER("heap_rprev");
+
+  if (info->lastinx < 0)
+    DBUG_RETURN(my_errno=HA_ERR_WRONG_INDEX);
+  keyinfo = share->keydef + info->lastinx;
+  if (keyinfo->algorithm == HA_KEY_ALG_BTREE)
+  {
+    heap_rb_param custom_arg;
+
+    /* If no active record and last was not deleted */
+    if (!(info->update & (HA_STATE_AKTIV | HA_STATE_NO_KEY |
+                          HA_STATE_DELETED)))
+    {
+      if (info->update & HA_STATE_PREV_FOUND)
+        pos= 0;                            /* Can't search before first row */
+      else
+      {
+        /* Last was 'next' after last record; search after last record */
+        pos= tree_search_edge(&keyinfo->rb_tree, info->parents,
+                              &info->last_pos, offsetof(TREE_ELEMENT, right));
+      }
+    }
+    else if (info->last_pos)
+      pos = tree_search_next(&keyinfo->rb_tree, &info->last_pos,
+                             offsetof(TREE_ELEMENT, right),
+                             offsetof(TREE_ELEMENT, left));
+    else
+    {
+      custom_arg.keyseg = keyinfo->seg;
+      custom_arg.key_length = keyinfo->length;
+      custom_arg.search_flag = SEARCH_SAME;
+      info->last_find_flag= HA_READ_KEY_OR_PREV;
+      pos = tree_search_key(&keyinfo->rb_tree, info->lastkey, info->parents, 
+                           &info->last_pos, info->last_find_flag, &custom_arg);
+    }
+    if (pos)
+    {
+      memcpy(&pos, pos + (*keyinfo->get_key_length)(keyinfo, pos),
+	     sizeof(uchar*));
+      info->current_ptr = pos;
+    }
+    else
+    {
+      my_errno = HA_ERR_KEY_NOT_FOUND;
+    }
+  }
+  else
+  {
+    if (info->current_ptr || (info->update & HA_STATE_NEXT_FOUND))
+    {
+      if ((info->update & HA_STATE_DELETED))
+        pos= hp_search(info, share->keydef + info->lastinx, info->lastkey, 3);
+      else
+        pos= hp_search(info, share->keydef + info->lastinx, info->lastkey, 2);
+    }
+    else
+    {
+      pos=0;					/* Read next after last */
+      my_errno=HA_ERR_KEY_NOT_FOUND;
+    }
+  }
+  if (!pos)
+  {
+    info->update=HA_STATE_PREV_FOUND;		/* For heap_rprev */
+    if (my_errno == HA_ERR_KEY_NOT_FOUND)
+      my_errno=HA_ERR_END_OF_FILE;
+    DBUG_RETURN(my_errno);
+  }
+  memcpy(record,pos,(size_t) share->reclength);
+  info->update=HA_STATE_AKTIV | HA_STATE_PREV_FOUND;
+  DBUG_RETURN(0);
+}
-- 
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