dontcopy flag counts towards DiskSpaceLabel

[JConstantine]

Here's the script file (Components.iss) from the Inno Setup Examples folder:

[Setup]
AppName=My Program
AppVersion=1.5
WizardStyle=modern
DefaultDirName={autopf}\My Program
DefaultGroupName=My Program
UninstallDisplayIcon={app}\MyProg.exe
OutputDir=userdocs:Inno Setup Examples Output

[Types]
Name: "full"; Description: "Full installation"
Name: "compact"; Description: "Compact installation"
Name: "custom"; Description: "Custom installation"; Flags: iscustom

[Components]
Name: "program"; Description: "Program Files"; Types: full compact custom; Flags: fixed
Name: "help"; Description: "Help File"; Types: full
Name: "readme"; Description: "Readme File"; Types: full
Name: "readme\en"; Description: "English"; Flags: exclusive
Name: "readme\de"; Description: "German"; Flags: exclusive

[Files]
Source: "MyProg.exe"; DestDir: "{app}"; Components: program
Source: "MyProg.chm"; DestDir: "{app}"; Components: help
Source: "Readme.txt"; DestDir: "{app}"; Components: readme\en; Flags: isreadme
Source: "Readme-German.txt"; DestName: "Liesmich.txt"; DestDir: "{app}"; Components: readme\de; Flags: isreadme

[Icons]
Name: "{group}\My Program"; Filename: "{app}\MyProg.exe"

DiskSpaceLabel shows 2.9 MB.

If I remove MyProg.chm from the Components like this:
Source: "MyProg.chm"; DestDir: "{app}"

DiskSpaceLabel is 3.0 MB.

If add dontcopy flag:

Source: "MyProg.chm"; DestDir: "{app}"; Flags: dontcopy

DiskSpaceLabel is still 3.0 MB instead of 2.9 MB.