bitbake: fetch2: improve handling of two classes of URL parameter mistakes

Handle the following situations in a URL (e.g. in SRC_URI):

* Trailing semicolon in a URL - this is now ignored.
* Parameter specified with no value (no equals sign). This still
  produces an error, but at least it is MalformedUrl with a proper
  message rather than "ValueError: need more than 1 value to unpack".

(Bitbake rev: bfd13dfbc4c9f1dd8315002271791b1d9e274989)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/fetch2/__init__.py

@@ -56,7 +56,10 @@ class BBFetchException(Exception):
 
 class MalformedUrl(BBFetchException):
     """Exception raised when encountering an invalid url"""
-    def __init__(self, url):
+    def __init__(self, url, message=''):
+         if message:
+             msg = message
+         else:
              msg = "The URL: '%s' is invalid and cannot be interpreted" % url
          self.url = url
          BBFetchException.__init__(self, msg)
@@ -371,6 +374,9 @@ def decodeurl(url):
     p = {}
     if parm:
         for s in parm.split(';'):
+            if s:
+                if not '=' in s:
+                    raise MalformedUrl(url, "The URL: '%s' is invalid: parameter %s does not specify a value (missing '=')" % (url, s))
                 s1, s2 = s.split('=')
                 p[s1] = s2