bk commit into 4.1 tree (sergefp:1.2629) BUG#26624

[Sergey Petrunia]

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ChangeSet@stripped, 2007-03-29 10:27:58+04:00, sergefp@stripped +1 -0
  BUG#26624: high mem usage (crash) in range optimizer
   - Post-review fixes

  sql/opt_range.cc@stripped, 2007-03-29 10:27:56+04:00, sergefp@stripped +15 -14
    BUG#26624: high mem usage (crash) in range optimizer
     - Post-review fixes

# 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:	sergefp
# Host:	pylon.mylan
# Root:	/home/psergey/mysql-4.1-bug26624-r2

--- 1.151/sql/opt_range.cc	2007-03-29 10:28:01 +04:00
+++ 1.152/sql/opt_range.cc	2007-03-29 10:28:01 +04:00
@@ -175,7 +175,7 @@
       Example:
         By induction: Let's take any interval on some keypart in the middle:
 
-           kp15=1 
+           kp15=c0
         
         Then let's AND it with this interval 'structure' from preceding and
         following keyparts:
@@ -184,18 +184,18 @@
         
         We will obtain this SEL_ARG graph:
  
-             kp14     $      kp15     $      kp16
-                      $               $
-         +---------+  $   +--------+  $   +---------+
-         | kp14=c1 |--$-->| kp15=1 |--$-->| kp16=c3 |
-         +---------+  $   +--------+  $   +---------+
-              |       $               $              
-         +---------+  $   +--------+  $             
-         | kp14=c2 |--$-->| kp15=1 |  $             
-         +---------+  $   +--------+  $             
-                      $               $
+             kp14     $      kp15      $      kp16
+                      $                $
+         +---------+  $   +---------+  $   +---------+
+         | kp14=c1 |--$-->| kp15=c0 |--$-->| kp16=c3 |
+         +---------+  $   +---------+  $   +---------+
+              |       $                $              
+         +---------+  $   +---------+  $             
+         | kp14=c2 |--$-->| kp15=c0 |  $             
+         +---------+  $   +---------+  $             
+                      $                $
                       
-       Note that we had to duplicate "kp15=1" and there was no way to avoid
+       Note that we had to duplicate "kp15=c0" and there was no way to avoid
        that. 
        The induction step: AND the obtained expression with another "wrapping"
        expression like (*).
@@ -477,7 +477,7 @@
     max_key[MAX_KEY_LENGTH+MAX_FIELD_WIDTH];
   bool quick;				// Don't calulate possible keys
   COND *cond;
-  /* Numbr of SEL_ARG objects allocated by SEL_ARG::clone_tree operations */
+  /* Number of SEL_ARG objects allocated by SEL_ARG::clone_tree operations */
   uint alloced_sel_args; 
 } PARAM;
 
@@ -681,7 +681,8 @@
     tmp->parent=new_parent;
     tmp->next_key_part=next_key_part;
     if (left != &null_element)
-      tmp->left=left->clone(param, tmp, next_arg);
+      if (!(tmp->left=left->clone(param, tmp, next_arg)))
+	return 0;				// OOM
 
     tmp->prev= *next_arg;			// Link into next/prev chain
     (*next_arg)->next=tmp;