Bug 1904776 - Allow dangling symlinks when unpacking upstream tarball with mach vendor r=glandium

As a side effect, also propagate dangling symlink option when called
recursively.

Differential Revision: https://phabricator.services.mozilla.com/D214924

python/mozbuild/mozbuild/vendor/vendor_manifest.py

@@ -604,7 +604,9 @@ class VendorManifest(MozbuildObject):
                 # Then copy over the directories
                 if self.should_perform_step("move-contents"):
                     self.logInfo({"d": vendor_dir}, "Copying to {d}.")
-                    mozfile.copy_contents(tmpextractdir.name, vendor_dir)
+                    mozfile.copy_contents(
+                        tmpextractdir.name, vendor_dir, ignore_dangling_symlinks=True
+                    )
                 else:
                     self.logInfo({}, "Skipping copying contents into tree.")
                     self._extract_directory = lambda: tmpextractdir.name

testing/mozbase/mozfile/mozfile/mozfile.py

@@ -332,7 +332,11 @@ def copy_contents(srcdir, dstdir, ignore_dangling_symlinks=False):
                     linkto = os.readlink(srcname)
                     os.symlink(linkto, dstname)
                 elif os.path.isdir(srcname):
-                    copy_contents(srcname, dstname)
+                    copy_contents(
+                        srcname,
+                        dstname,
+                        ignore_dangling_symlinks=ignore_dangling_symlinks,
+                    )
                 else:
                     _call_windows_retry(shutil.copy2, (srcname, dstname))
             except OSError as why: