Visual Studio solution generated by qmake replaces dashes in project filenames with underscore, but project generator does not

Reproducible like this:

First project file:
TEMPLATE = subdirs
TARGET = MySolution
SUBDIRS = \
MySubFolder \

Project file in MySubFolder
TEMPLATE = lib
TARGET = One-Two

Run

qmake -tp vc -r -spec win32-msvc2008

which will print

Reading C:/bugs/MySubFolder/MySubFolder
WARNING: Ignored (not found) 'C:/bugs/MySubFolder\One_Two.vcproj'

A project file One-Two.vcproj exists after this in MySubFolder, and can be loaded into Visual Studio 2008 without problems (dash is correctly displayed).