clone: do not delete the target if only the update fails

mercurial/hg.py

@@ -212,6 +212,9 b' def clone(ui, source, dest=None, pull=Fa'
     if src_lock:
         src_lock.release()
 
+    if dir_cleanup:
+        dir_cleanup.close()
+
     if dest_repo.local():
         fp = dest_repo.opener("hgrc", "w", text=True)
         fp.write("[paths]\n")
@@ -227,8 +230,6 b' def clone(ui, source, dest=None, pull=Fa'
             except:
                 checkout = dest_repo.changelog.tip()
             _update(dest_repo, checkout)
-    if dir_cleanup:
-        dir_cleanup.close()
 
     return src_repo, dest_repo