manifest: normalize name & path when constructing fs paths

If the manifest uses a trailing slash on the name attribute, repo
will construct bad internal filesystem paths which confuses tools
later on.

For example, this manifest entry:
  <project name="aosp/platform/system/libhidl/" ...
will cause repo to use paths like:
  .repo/project-objects/aosp/platform/system/libhidl/.git/
when it really should be using:
  .repo/project-objects/aosp/platform/system/libhidl.git

Apply the normalization when we construct the local filesystem paths
as we cannot guarantee that the remote URL constructed from these
will behave the same.  A server might really want:
  https://example.com/aosp/platform/system/libhidl/
and would throw an error if we instead tried to fetch:
  https://example.com/aosp/platform/system/libhidl

Unfortunately, any existing repo client checkouts that use such a
manifest will hit a one-time sync error as the internal git location
has changed.  I'm not sure there's a way to cleanly migrate that.

Bug: https://crbug.com/1086043
Change-Id: I30bea0ffd23e478de89a035f408055e48a102658
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/268742
Tested-by: Mike Frysinger <vapier@google.com>
Reviewed-by: David Pursehouse <dpursehouse@digital.ai>

manifest_xml.py

@@ -978,6 +978,10 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
     return project
 
   def GetProjectPaths(self, name, path):
+    # The manifest entries might have trailing slashes.  Normalize them to avoid
+    # unexpected filesystem behavior since we do string concatenation below.
+    path = path.rstrip('/')
+    name = name.rstrip('/')
     use_git_worktrees = False
     relpath = path
     if self.IsMirror:
@@ -1010,6 +1014,10 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
     return os.path.relpath(relpath, parent_relpath)
 
   def GetSubprojectPaths(self, parent, name, path):
+    # The manifest entries might have trailing slashes.  Normalize them to avoid
+    # unexpected filesystem behavior since we do string concatenation below.
+    path = path.rstrip('/')
+    name = name.rstrip('/')
     relpath = self._JoinRelpath(parent.relpath, path)
     gitdir = os.path.join(parent.gitdir, 'subprojects', '%s.git' % path)
     objdir = os.path.join(parent.gitdir, 'subproject-objects', '%s.git' % name)