Fix small bug in udf_example.cc, it was processing one char too much and thus returning junk

Add more DBUG_PRINT's in udf_handler::val_str
Enable udf.test


mysql-test/t/disabled.def:
  Enable udf.test
sql/item_func.cc:
  Add DBUG_ printouts for easier debugging of installed udf's
sql/udf_example.cc:
  Bug fix, break for loop when "n < n_end"

mysql-test/t/disabled.def

@@ -11,4 +11,3 @@
 ##############################################################################
 
 ndb_load        : Bug#17233
-udf             : Not yet            

sql/item_func.cc

@@ -2734,9 +2734,10 @@ String *udf_handler::val_str(String *str,String *save_str)
 {
   uchar is_null_tmp=0;
   ulong res_length;
+  DBUG_ENTER("udf_handler::val_str");
 
   if (get_arguments())
-    return 0;
+    DBUG_RETURN(0);
   char * (*func)(UDF_INIT *, UDF_ARGS *, char *, ulong *, uchar *, uchar *)=
     (char* (*)(UDF_INIT *, UDF_ARGS *, char *, ulong *, uchar *, uchar *))
     u_d->func;
@@ -2746,22 +2747,26 @@ String *udf_handler::val_str(String *str,String *save_str)
     if (str->alloc(MAX_FIELD_WIDTH))
     {
       error=1;
-      return 0;
+      DBUG_RETURN(0);
     }
   }
   char *res=func(&initid, &f_args, (char*) str->ptr(), &res_length,
 		 &is_null_tmp, &error);
+  DBUG_PRINT("info", ("udf func returned, res_length: %lu", res_length));
   if (is_null_tmp || !res || error)		// The !res is for safety
   {
-    return 0;
+    DBUG_PRINT("info", ("Null or error"));
+    DBUG_RETURN(0);
   }
   if (res == str->ptr())
   {
     str->length(res_length);
-    return str;
+    DBUG_PRINT("exit", ("str: %s", str->ptr()));
+    DBUG_RETURN(str);
   }
   save_str->set(res, res_length, str->charset());
-  return save_str;
+  DBUG_PRINT("exit", ("save_str: %s", save_str->ptr()));
+  DBUG_RETURN(save_str);
 }
 
 

sql/udf_example.cc

@@ -344,7 +344,7 @@ char *metaphon(UDF_INIT *initid, UDF_ARGS *args, char *result,
   KSflag = 0; /* state flag for KS translation */
 
   for (metaph_end = result + MAXMETAPH, n_start = n;
-	n <= n_end && result < metaph_end; n++ )
+	n < n_end && result < metaph_end; n++ )
   {
 
     if ( KSflag )