bitbake: fetch2: Ensure a valid symlink in PREMIRRORS case when using shallow cloning

- Since `ud.path` contains in that case the `PREMIRRORS` prefix path,
  this change ensures that a correct symlink is set up.

(Bitbake rev: 37ed18e45aa17406162efc5ee3ddb2d6b33d07b9)

Signed-off-by: Stefan Koch <stefan-koch@siemens.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/fetch2/__init__.py

@@ -1117,7 +1117,10 @@ def try_mirror_url(fetch, origud, ud, ld, check = False):
                     origud.method.build_mirror_data(origud, ld)
             return origud.localpath
         # Otherwise the result is a local file:// and we symlink to it
-        ensure_symlink(ud.localpath, origud.localpath)
+        # This may also be a link to a shallow archive
+        # When using shallow mode, add a symlink to the original fullshallow
+        # path to ensure a valid symlink even in the `PREMIRRORS` case
+        origud.method.update_mirror_links(ud, origud)
         update_stamp(origud, ld)
         return ud.localpath
 
@@ -1653,6 +1656,11 @@ class FetchMethod(object):
             except FileExistsError:
                 pass
 
+    def update_mirror_links(self, ud, origud):
+        # For local file:// results, create a symlink to them
+        # This may also be a link to a shallow archive
+        self.ensure_symlink(ud.localpath, origud.localpath)
+
     def try_premirror(self, urldata, d):
         """
         Should premirrors be used?

bitbake/lib/bb/fetch2/git.py

@@ -348,6 +348,13 @@ class Git(FetchMethod):
     def tarball_need_update(self, ud):
         return ud.write_tarballs and not os.path.exists(ud.fullmirror)
 
+    def update_mirror_links(self, ud, origud):
+        super().update_mirror_links(ud, origud)
+        # When using shallow mode, add a symlink to the original fullshallow
+        # path to ensure a valid symlink even in the `PREMIRRORS` case
+        if ud.shallow and not os.path.exists(origud.fullshallow):
+            self.ensure_symlink(ud.localpath, origud.fullshallow)
+
     def try_premirror(self, ud, d):
         # If we don't do this, updating an existing checkout with only premirrors
         # is not possible