Why does Microsoft's source code reference have two copies of the code in each .cs file

Question

So, I was looking in [PATH]\RefSrc\Source\.Net\4.0\DEVDIV_TFS\Dev10\Releases\RTMRel\ndp\fx\src\MIT\System\Web\UI\MobileControls\Panel.cs\1305376\Panel.cs and noticed that the file, as well as other files I checked, contained two exact duplicates (I checked by pasting both chunks into a diff tool) of the source code. Like so:

[COPYRIGHT MESSAGE 1]    
[CODE]    
[COPYRIGHT MESSAGE 2]
[COPYRIGHT MESSAGE 1]    
[CODE]    
[COPYRIGHT MESSAGE 2]

Is there a reason for this? Some weirdness with version control or something?

I tried checking the Reference Source Forum and saw someone theorized that it's a bug in the installer, but I am curious if anyone can offer their own insight.

Answer 1

Redundancy, when the first source is corrupt it gets validated or synchronized with the other.