Backported patches to DD4hep master

Incorporate critical patches to DD4hep (back ported from master):

• https://github.com/AIDASoft/DD4hep/pull/849
• https://github.com/AIDASoft/DD4hep/pull/851

spack/packages/dd4hep/package.py

@@ -25,8 +25,8 @@ class Dd4hep(CMakePackage):
 
     version('master', branch='master')
     version('2021-07-27',
-            sha257='e472500345d02695f0403911f29e95676fd84e6dcba7180299c37378f0ff8125',
-            url='https://github.com/AIDASoft/DD4hep/archive/f2da87ba9366e5ad1a4ff0369788d61e05c62dd0.tar.gz')
+             sha256='e472500345d02695f0403911f29e95676fd84e6dcba7180299c37378f0ff8125',
+             url='https://github.com/AIDASoft/DD4hep/archive/f2da87ba9366e5ad1a4ff0369788d61e05c62dd0.tar.gz')
     version('1.17', sha256='036a9908aaf1e13eaf5f2f43b6f5f4a8bdda8183ddc5befa77a4448dbb485826')
     version('1.16.1', sha256='c8b1312aa88283986f89cc008d317b3476027fd146fdb586f9f1fbbb47763f1a')
     version('1.16', sha256='ea9755cd255cf1b058e0e3cd743101ca9ca5ff79f4c60be89f9ba72b1ae5ec69')
@@ -114,14 +114,18 @@ class Dd4hep(CMakePackage):
         env.set("DD4hep_ROOT", self.prefix)
 
     def url_for_version(self, version):
+	# dd4hep releases are dashes and padded with a leading zero
+        # the patch version is omitted when 0
+        # so for example v01-12-01, v01-12 ...
+
+        if not isinstance(version, Version):
+            version = Version(version)
+
         # If we have a specific URL for this version, don't extrapolate.
         version_urls = self.version_urls()
         if version in version_urls:
             return version_urls[version]
 
-        # dd4hep releases are dashes and padded with a leading zero
-        # the patch version is omitted when 0
-        # so for example v01-12-01, v01-12 ...
         base_url = self.url.rsplit('/', 1)[0]
         if len(version) == 1:
             major = version[0]