[PATCH][dunfell] bitbake: fetch2: add check for empty SRC_URI hash string

[Jose Quaresma <quaresma.jose@gmail.com>]

From: Scott Weaver <weaverjs@gmail.com>

No error was being reported when the hash string was set to empty.
For example: SRC_URI[md5sum] = ""

On a related note (not a bug):
Because whitespace in the string will result in a checksum mismatch, the error
message was updated to make it a little clearer why the error was thrown.
For example: SRC_URI[md5sum] = " " or
SRC_URI[md5sum] = " 209f8326f5137d8817a6276d9577a2f1"

Now creates a message like this:
File: '/home/scott/yocto-cache/downloads/rsync-3.2.3.tar.gz' has md5
checksum '209f8326f5137d8817a6276d9577a2f1' when ' 209f8326f5137d8817a6276d9577a2f1' was expected

[YOCTO #14232]

(Bitbake rev: a13510d0028e234ea2f4744b0d0c38558395c70f)

Signed-off-by: Scott Weaver <weaverjs@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Jose Quaresma <quaresma.jose@gmail.com>
---
 bitbake/lib/bb/fetch2/__init__.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/bitbake/lib/bb/fetch2/__init__.py b/bitbake/lib/bb/fetch2/__init__.py
index dc99914cd9..3e6555bd67 100644
--- a/bitbake/lib/bb/fetch2/__init__.py
+++ b/bitbake/lib/bb/fetch2/__init__.py
@@ -562,6 +562,9 @@ def verify_checksum(ud, d, precomputed={}):
 
         checksum_expected = getattr(ud, "%s_expected" % checksum_id)
 
+        if checksum_expected == '':
+            checksum_expected = None
+
         return {
             "id": checksum_id,
             "name": checksum_name,
@@ -612,7 +615,7 @@ def verify_checksum(ud, d, precomputed={}):
 
     for ci in checksum_infos:
         if ci["expected"] and ci["expected"] != ci["data"]:
-            messages.append("File: '%s' has %s checksum %s when %s was " \
+            messages.append("File: '%s' has %s checksum '%s' when '%s' was " \
                             "expected" % (ud.localpath, ci["id"], ci["data"], ci["expected"]))
             bad_checksum = ci["data"]
 
-- 
2.35.1