building: Allow usage of VSVersionInfo again.

Fixes pyinstaller#4381: The option to pass a VSVersionInfo object as version
argument to EXE was a feature that was explicitly implemented,
but was overlooked when attempts were made to make paths relative.
The bug is fixed by checking whether the object passed as version
argument is a VSVersionInfo object. This change explicitly only
checks if it is a VSVersionInfo object, if not it is still assumed
to be a path-like object.

PyInstaller/building/api.py

@@ -422,7 +422,8 @@ def __init__(self, *args, **kwargs):
                                  "", "OPTION"))
 
             if self.versrsrc:
-                if not os.path.isabs(self.versrsrc):
+                if (not isinstance(self.versrsrc, versioninfo.VSVersionInfo)
+                    and not os.path.isabs(self.versrsrc)):
                     # relative version-info path is relative to spec file
                     self.versrsrc = os.path.join(
                         CONF['specpath'], self.versrsrc)

news/4381.bugfix.rst

@@ -0,0 +1 @@
+(Windows) Allow usage of `VSVersionInfo` as version argument to EXE again.

news/4539.bugfix.rst

@@ -0,0 +1 @@
+(Windows) Allow usage of `VSVersionInfo` as version argument to EXE again.