Merge 5.0-bugteam -> 5.1-bugteam

1 files changed, 11 insertions, 1 deletions

diff --git a/sql/field.cc b/sql/field.cc
index b03cc140ade..16bf0fdb070 100644
--- a/sql/field.cc
+++ b/sql/field.cc
@@ -7699,8 +7699,18 @@ int Field_blob::store(const char *from,uint length,CHARSET_INFO *cs)
     return 0;
   }
 
-  if (from == value.ptr())
+  /*
+    If the 'from' address is in the range of the temporary 'value'-
+    object we need to copy the content to a different location or it will be
+    invalidated when the 'value'-object is reallocated to make room for
+    the new character set.
+  */
+  if (from >= value.ptr() && from <= value.ptr()+value.length())
   {
+    /*
+      If content of the 'from'-address is cached in the 'value'-object
+      it is possible that the content needs a character conversion.
+    */
     uint32 dummy_offset;
     if (!String::needs_conversion(length, cs, field_charset, &dummy_offset))
     {