[git-webkit] Error message for git webkit commit for non existing iss…

…ues could be improved.

rdar://122151119
https://bugs.webkit.org/show_bug.cgi?id=268134

Reviewed by Jonathan Bedard.

Added reason for failure and cleaned up error.

* Tools/Scripts/libraries/webkitbugspy/webkitbugspy/bugzilla.py:
(Tracker.populate): If the bug does not exist, populate returns None and prints an error message. This should help future error handling as well.
* Tools/Scripts/libraries/webkitscmpy/webkitscmpy/program/commit.py:
(Commit.main):

Canonical link: https://commits.webkit.org/274756@main

Tools/Scripts/libraries/webkitbugspy/webkitbugspy/bugzilla.py

@@ -214,6 +214,9 @@ def populate(self, issue, member=None):
             )
             if response.status_code // 100 == 4 and self._logins_left:
                 self._logins_left -= 1
+                if response.json().get('code') == 101:
+                    sys.stderr.write("{}\n".format(response.json().get('message')))
+                    return None
             response = response.json().get('bugs', []) if response.status_code == 200 else None
             if response:
                 response = response[0]

Tools/Scripts/libraries/webkitscmpy/webkitscmpy/program/commit.py

@@ -85,7 +85,7 @@ def main(cls, args, repository, command=None, representation=None, **kwargs):
                 issue = Tracker.instance().issue(int(args.issue))
             else:
                 issue = Tracker.from_string(args.issue)
-            if not issue:
+            if not issue or not issue.title:
                 sys.stderr.write("'{}' cannot be converted to an issue\n".format(args.issue))
                 return 1