Merge epotemkin@bk-internal.mysql.com:/home/bk/mysql-5.0-opt

into  moonbone.local:/mnt/gentoo64/work/bk-trees/mysql-5.1-opt


mysql-test/r/explain.result:
  Auto merged
mysql-test/r/func_default.result:
  Auto merged
mysql-test/r/func_regexp.result:
  Auto merged
mysql-test/r/func_test.result:
  Auto merged
mysql-test/r/having.result:
  Auto merged
mysql-test/r/olap.result:
  Auto merged
mysql-test/r/subselect.result:
  Auto merged
mysql-test/r/union.result:
  Auto merged
mysql-test/r/varbinary.result:
  Auto merged
sql/item.cc:
  Auto merged
sql/item.h:
  Auto merged
sql/item_strfunc.cc:
  Auto merged
sql/opt_range.cc:
  Auto merged
sql/sql_union.cc:
  Auto merged
mysql-test/r/func_str.result:
  Manually merged
mysql-test/t/func_str.test:
  Manually merged

1 files changed, 8 insertions, 9 deletions

diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index b96567cf1ff..a011a2884c8 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -964,18 +964,18 @@ String *Item_func_insert::val_str(String *str)
       args[3]->null_value)
     goto null; /* purecov: inspected */
 
-  if ((start < 0) || (start > res->length() + 1))
+  if ((start < 0) || (start > res->length()))
     return res;                                 // Wrong param; skip insert
-  if ((length < 0) || (length > res->length() + 1))
-    length= res->length() + 1;
+  if ((length < 0) || (length > res->length()))
+    length= res->length();
 
   /* start and length are now sufficiently valid to pass to charpos function */
    start= res->charpos((int) start);
    length= res->charpos((int) length, (uint32) start);
 
   /* Re-testing with corrected params */
-  if (start > res->length() + 1)
-    return res;                                 // Wrong param; skip insert
+  if (start > res->length())
+    return res; /* purecov: inspected */        // Wrong param; skip insert
   if (length > res->length() - start)
     length= res->length() - start;
 
@@ -1181,11 +1181,10 @@ void Item_func_substr::fix_length_and_dec()
   if (args[1]->const_item())
   {
     int32 start= (int32) args[1]->val_int();
-    start= (int32)((start < 0) ? max_length + start : start - 1);
-    if (start < 0 || start >= (int32) max_length)
-      max_length=0; /* purecov: inspected */
+    if (start < 0)
+      max_length= ((uint)(-start) > max_length) ? 0 : (uint)(-start);
     else
-      max_length-= (uint) start;
+      max_length-= min((uint)(start - 1), max_length);
   }
   if (arg_count == 3 && args[2]->const_item())
   {