[Rd] Merge (PR#9699)

[edward.m at psu.ac.th]

Full_Name: Edward McNeil
Version: 2.5.0
OS: Windows XP
Submission from: (NULL) (203.170.234.5)


This is a new bug introduced to R2.5.0. 

Scenario: If one of the data frames to merge contains two variables that have
the same name, then the data in first variable (of the same name) is copied to
the second variable in the resulting merged data frame. 

In R2.4.1, the second variable name is automatically renamed (in the resulting
data frame) by adding ".1" to the end. R2.5.0 doesn't seem to do this anymore.