bk commit into 4.0 tree (istruewing:1.2193)

[ingo]

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4.0 repository of istruewing. When istruewing does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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ChangeSet@stripped, 2006-09-22 15:03:50+02:00, istruewing@stripped +1 -0
  Merge chilla.local:/home/mydev/mysql-4.0--team
  into  chilla.local:/home/mydev/mysql-4.0-bug14400
  MERGE: 1.2182.1.2

  myisam/mi_rkey.c@stripped, 2006-09-22 15:03:50+02:00, istruewing@stripped +0 -13
    Bug#14400 - Query joins wrong rows from table which is subject of
                "concurrent insert"
    Manual merge
    MERGE: 1.14.1.2

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	istruewing
# Host:	chilla.local
# Root:	/home/mydev/mysql-4.0-bug14400/RESYNC

--- 1.15/myisam/mi_rkey.c	2006-09-22 15:03:52 +02:00
+++ 1.16/myisam/mi_rkey.c	2006-09-22 15:03:52 +02:00
@@ -79,28 +79,42 @@ int mi_rkey(MI_INFO *info, byte *buf, in
 		  myisam_read_vec[search_flag], info->s->state.key_root[inx]))
   {
     /*
-      If we are searching for an exact key (including the data pointer)
-      and this was added by an concurrent insert,
-      then the result is "key not found".
+      If we searching for a partial key (or using >, >=, < or <=) and
+      the data is outside of the data file, we need to continue searching
+      for the first key inside the data file
     */
-    if ((search_flag == HA_READ_KEY_EXACT) &&
-        (info->lastpos >= info->state->data_file_length))
+    if (info->lastpos >= info->state->data_file_length &&
+        (search_flag != HA_READ_KEY_EXACT ||
+         last_used_keyseg != keyinfo->seg + keyinfo->keysegs))
     {
-      my_errno= HA_ERR_KEY_NOT_FOUND;
-      info->lastpos= HA_OFFSET_ERROR;
-    }
-    else while (info->lastpos >= info->state->data_file_length)
-    {
-      /*
-	Skip rows that are inserted by other threads since we got a lock
-	Note that this can only happen if we are not searching after an
-	exact key, because the keys are sorted according to position
-      */
-      if  (_mi_search_next(info, keyinfo, info->lastkey,
-			   info->lastkey_length,
-			   myisam_readnext_vec[search_flag],
-			   info->s->state.key_root[inx]))
-	break;
+      do
+      {
+        uint not_used;
+        /*
+          Skip rows that are inserted by other threads since we got a lock
+          Note that this can only happen if we are not searching after an
+          full length exact key, because the keys are sorted
+          according to position
+        */
+        if  (_mi_search_next(info, keyinfo, info->lastkey,
+                             info->lastkey_length,
+                             myisam_readnext_vec[search_flag],
+                             info->s->state.key_root[inx]))
+          break;
+        /*
+          Check that the found key does still match the search.
+          _mi_search_next() delivers the next key regardless of its
+          value.
+        */
+        if (search_flag == HA_READ_KEY_EXACT &&
+            _mi_key_cmp(keyinfo->seg, key_buff, info->lastkey, use_key_length,
+                        SEARCH_FIND, &not_used))
+        {
+          my_errno= HA_ERR_KEY_NOT_FOUND;
+          info->lastpos= HA_OFFSET_ERROR;
+          break;
+        }
+      } while (info->lastpos >= info->state->data_file_length);
     }
   }