Fixed LP bug #823301.

A bug in the code of the function key_or could lead to a situation
when performing of an OR operation for one index changes the result
the operation for another index. This bug is fixed with this patch.

Also corrected the specification and the code of the function 
or_sel_tree_with_checks.

1 files changed, 16 insertions, 12 deletions

diff --git a/sql/opt_range.cc b/sql/opt_range.cc
index 3ed975a59bb..815a6f5f316 100644
--- a/sql/opt_range.cc
+++ b/sql/opt_range.cc
@@ -1136,10 +1136,10 @@ int SEL_IMERGE::and_sel_tree(RANGE_OPT_PARAM *param, SEL_TREE *tree,
 
     2. In the second mode, when is_first_check_pass==FALSE :
       2.1. For each rt_j in the imerge that can be ored (see the function
-           sel_trees_can_be_ored), but not must be ored, with rt the function
-           replaces rt_j for a range tree such that for each index for which
-           ranges are defined in both in rt_j and rt  the tree contains the
-           result of oring of these ranges.
+           sel_trees_can_be_ored) with rt the function replaces rt_j for a
+           range tree such that for each index for which ranges are defined
+           in both in rt_j and rt  the tree contains the  result of oring of
+           these ranges.
       2.2. In other cases the function does not produce any imerge.
 
     When is_first_check==TRUE the function returns FALSE in the parameter
@@ -1163,7 +1163,7 @@ int SEL_IMERGE::or_sel_tree_with_checks(RANGE_OPT_PARAM *param,
                                         bool *is_last_check_pass)
 {
   bool was_ored= FALSE;
-  *is_last_check_pass= TRUE;
+  *is_last_check_pass= is_first_check_pass;
   SEL_TREE** or_tree = trees;
   for (uint i= 0; i < n_trees; i++, or_tree++)
   {
@@ -1174,7 +1174,7 @@ int SEL_IMERGE::or_sel_tree_with_checks(RANGE_OPT_PARAM *param,
     {
       bool must_be_ored= sel_trees_must_be_ored(param, *or_tree, tree,
                                                 ored_keys);
-      if (must_be_ored || !is_first_check_pass) 
+      if (must_be_ored || !is_first_check_pass)
       {
         result_keys.clear_all();
         result= *or_tree;
@@ -1210,22 +1210,19 @@ int SEL_IMERGE::or_sel_tree_with_checks(RANGE_OPT_PARAM *param,
     {
       if (result_keys.is_clear_all())
         result->type= SEL_TREE::ALWAYS;
-      *is_last_check_pass= TRUE;
       if ((result->type == SEL_TREE::MAYBE) ||
           (result->type == SEL_TREE::ALWAYS))
         return 1;
       /* SEL_TREE::IMPOSSIBLE is impossible here */
       result->keys_map= result_keys; 
       *or_tree= result;
-      if (is_first_check_pass)
-        return 0;
       was_ored= TRUE;
     }
   }
   if (was_ored)
     return 0;
 
-  if (!*is_last_check_pass && 
+  if (is_first_check_pass && !*is_last_check_pass &&
       !(tree= new SEL_TREE(tree, FALSE, param)))
     return (-1);
   return or_sel_tree(param, tree);
@@ -8382,9 +8379,9 @@ tree_or(RANGE_OPT_PARAM *param,SEL_TREE *tree1,SEL_TREE *tree2)
     /* Build the imerge part of the tree for the formula (1) */
     SEL_TREE *rt1= tree1;
     SEL_TREE *rt2= tree2;
-    if (!no_merges1)
+    if (no_merges1)
       rt1= new SEL_TREE(tree1, TRUE, param);
-    if (!no_merges2)
+    if (no_merges2)
       rt2= new SEL_TREE(tree2, TRUE, param);
     if (!rt1 || !rt2 ||
         result->merges.push_back(imerge_from_ranges) ||
@@ -9079,6 +9076,13 @@ key_or(RANGE_OPT_PARAM *param, SEL_ARG *key1,SEL_ARG *key2)
             key2:               [---]
             tmp:     [---------]
           */
+          if (key2->use_count)
+	  {
+	    SEL_ARG *key2_cpy= new SEL_ARG(*key2);
+            if (key2_cpy)
+              return 0;
+            key2= key2_cpy;
+	  }
           key2->copy_max_to_min(tmp);
           continue;
         }