bad branch names in recipes produce oopses

Errors specifying branches produce oopses like the those shown below. Instead, a validation error should be shown.

The oopses are different depending one whether the incorrectly-specified branch is the base branch or part of the recipe instructions.

Oops!

Sorry, something just went wrong in Launchpad.

We’ve recorded what happened, and we’ll fix it as soon as possible. Apologies for the inconvenience.

(Error ID: OOPS-1623DF8)

This server runs pre-release code, so it's possible this problem doesn't affect launchpad.net. If you're a member of the Launchpad Beta Testers team, you can disable redirection in order to use launchpad.net.

Disable redirection for 2 hours

Traceback (most recent call last):

    * Module zope.publisher.publish, line 134, in publish
      result = publication.callObject(request, obj)
    * Module canonical.launchpad.webapp.publication, line 436, in callObject
      return mapply(ob, request.getPositionalArguments(), request)
    * Module zope.publisher.publish, line 109, in mapply
      return debug_call(obj, args)
      __traceback_info__: <security proxied zope.browserpage.metaconfigure.SimpleViewClass from /srv/launchpad.net/codelines/current/lib/lp/app/templates/generic-edit.pt instance at 0xe36e7ec>
    * Module zope.publisher.publish, line 115, in debug_call
      return obj(*args)
    * Module canonical.launchpad.webapp.publisher, line 274, in __call__
      self.initialize()
    * Module canonical.launchpad.webapp.launchpadform, line 111, in initialize
      self.form_result = action.success(data)
    * Module zope.formlib.form, line 606, in success
      return self.success_handler(self.form, self, data)
    * Module lp.code.browser.sourcepackagerecipe, line 405, in request_action
      self.context.builder_recipe = recipe
    * Module lp.code.model.sourcepackagerecipe, line 104, in _set_builder_recipe
      self._recipe_data.setRecipe(value)
    * Module lp.code.model.sourcepackagerecipedata, line 235, in setRecipe
      raise NoSuchBranch(builder_recipe.url)

NoSuchBranch: No such branch: 'bzr-pipeline'.<br />

Oops!

Sorry, something just went wrong in Launchpad.

We’ve recorded what happened, and we’ll fix it as soon as possible. Apologies for the inconvenience.

(Error ID: OOPS-1623DF9)

This server runs pre-release code, so it's possible this problem doesn't affect launchpad.net. If you're a member of the Launchpad Beta Testers team, you can disable redirection in order to use launchpad.net.

Disable redirection for 2 hours

Traceback (most recent call last):

    * Module zope.publisher.publish, line 134, in publish
      result = publication.callObject(request, obj)
    * Module canonical.launchpad.webapp.publication, line 436, in callObject
      return mapply(ob, request.getPositionalArguments(), request)
    * Module zope.publisher.publish, line 109, in mapply
      return debug_call(obj, args)
      __traceback_info__: <security proxied zope.browserpage.metaconfigure.SimpleViewClass from /srv/launchpad.net/codelines/current/lib/lp/app/templates/generic-edit.pt instance at 0x4214da0c>
    * Module zope.publisher.publish, line 115, in debug_call
      return obj(*args)
    * Module canonical.launchpad.webapp.publisher, line 274, in __call__
      self.initialize()
    * Module canonical.launchpad.webapp.launchpadform, line 111, in initialize
      self.form_result = action.success(data)
    * Module zope.formlib.form, line 606, in success
      return self.success_handler(self.form, self, data)
    * Module lp.code.browser.sourcepackagerecipe, line 405, in request_action
      self.context.builder_recipe = recipe
    * Module lp.code.model.sourcepackagerecipe, line 104, in _set_builder_recipe
      self._recipe_data.setRecipe(value)
    * Module lp.code.model.sourcepackagerecipedata, line 239, in setRecipe
      builder_recipe, parent_insn=None, branch_map=branch_map)
    * Module lp.code.model.sourcepackagerecipedata, line 218, in _recordInstructions
      instruction.nest_path, self, parent_insn)
    * Module lp.code.model.sourcepackagerecipedata, line 63, in __init__
      self.branch = branch
    * Module storm.references, line 185, in __set__
      self._relation.unlink(get_obj_info(local), remote_info, True)
    * Module storm.references, line 717, in unlink
      local_vars[local_column].set(None)
    * Module storm.variables, line 72, in raise_none_error
      raise NoneError("None isn't acceptable as a value for %s" % name)

NoneError: None isn't acceptable as a value for SourcePackageRecipeDataInstruction.branch<br />