Add another table to store linked_revs

We need to create fake revisions when packages were touched that are
linked themselves

lib/db_revision.py

@@ -25,7 +25,7 @@ class DBRevision:
         self._hash = None
 
     def __str__(self):
-        return f"Rev {self.project}/{self.rev} Md5 {self.unexpanded_srcmd5} {self.commit_time} {self.userid} {self.request_number}"
+        return f"Rev {self.project}/{self.package}/{self.rev} Md5 {self.unexpanded_srcmd5} {self.commit_time} {self.userid} {self.request_number}"
 
     def __repr__(self):
         return f"[{self.__str__()}]"
@@ -119,6 +119,8 @@ class DBRevision:
         return ret
 
     def linked_rev(self, db):
+        if self.broken:
+            return None
         with db.cursor() as cur:
             cur.execute(
                 "SELECT project,package FROM links where revision_id=%s", (self.dbid,)
@@ -134,6 +136,8 @@ class DBRevision:
             revisions = [DBRevision(row) for row in cur.fetchall()]
         if revisions:
             return revisions[0]
+        else:
+            self.set_broken(db)
         return None
 
     def set_broken(self, db):