Bug#5005 collation cp852_bin makes server crash

ctype-simple.c:
  Check that unicode map was loaded
cp852.xml:
  Missing cp852_bin was added.

sql/share/charsets/cp852.xml

@@ -114,6 +114,8 @@
 </map>
 </collation>
 
+<collation name="cp852_bin"	flag="binary"/>
+
 </charset>
 
 </charsets>

strings/ctype-simple.c

@@ -1171,6 +1171,15 @@ static my_bool create_fromuni(CHARSET_INFO *cs, void *(*alloc)(uint))
   uni_idx	idx[PLANE_NUM];
   int		i,n;
   
+  /*
+    Check that Unicode map is loaded.
+    It can be not loaded when the collation is
+    listed in Index.xml but not specified
+    in the character set specific XML file.
+  */
+  if (!cs->tab_to_uni)
+    return TRUE;
+  
   /* Clear plane statistics */
   bzero(idx,sizeof(idx));