[PATCH v2] npmsw fetcher: Avoid instantiating Fetch class if url list is empty

[PATCH v2] npmsw fetcher: Avoid instantiating Fetch class if url list is empty

[Svend Meyland Nicolaisen]

Recipes containing both git and npmsw sources in the SRC_URI fail
during fetch from the shrinkwrap. It seems that when the fetcher is
fetching from the shrinkwrap, the SRCREV variable has been deleted but it
till ends up fetching from the git source resulting in an error because
SRCREV is undefined. The root cause of this is that the Fetch class defaults
to urls from the SRC_URI when the urls parameter contains an empty list. This
patch will ensure that Fetch is not instantiated if the urls list is empty.

Signed-off-by: Svend Meyland Nicolaisen <public@smn.dk>
---
 lib/bb/fetch2/npmsw.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/bb/fetch2/npmsw.py b/lib/bb/fetch2/npmsw.py
index 36fcbfba..cc81100b 100644
--- a/lib/bb/fetch2/npmsw.py
+++ b/lib/bb/fetch2/npmsw.py
@@ -205,7 +205,9 @@ class NpmShrinkWrap(FetchMethod):
         # This fetcher resolves multiple URIs from a shrinkwrap file and then
         # forwards it to a proxy fetcher. The management of the donestamp file,
         # the lockfile and the checksums are forwarded to the proxy fetcher.
-        ud.proxy = Fetch([dep["url"] for dep in ud.deps if dep["url"]], data)
+        shrinkwrap_urls = [dep["url"] for dep in ud.deps if dep["url"]]
+        if shrinkwrap_urls:
+            ud.proxy = Fetch(shrinkwrap_urls, data)
         ud.needdonestamp = False
 
     @staticmethod
-- 
2.40.0.windows.1