Bug 1520340 - Move old_configure_assignments formatting to prepare_configure. r=froydnj

Depends on D16619

Differential Revision: https://phabricator.services.mozilla.com/D16620

--HG--
extra : moz-landing-system : lando

build/moz.configure/old.configure

@@ -147,8 +147,8 @@ def prepare_configure(old_configure, mozconfig, autoconf, build_env, shell,
         # mozconfig['make_extra'], which we don't pass automatically above.
         inject('export AUTOCONF=%s' % quote(autoconf))
 
-        for assignment in old_configure_assignments:
-            inject(assignment)
+        for k, v in old_configure_assignments:
+            inject('%s=%s' % (k, quote(v)))
 
     return cmd
 

build/moz.configure/util.configure

@@ -486,13 +486,13 @@ def add_old_configure_assignment(var, value, when=None):
         if var is None or value is None:
             return
         if value is True:
-            assignments.append('%s=1' % var)
+            assignments.append((var, '1'))
         elif value is False:
-            assignments.append('%s=' % var)
+            assignments.append((var, ''))
         else:
             if isinstance(value, (list, tuple)):
                 value = quote(*value)
-            assignments.append('%s=%s' % (var, quote(str(value))))
+            assignments.append((var, str(value)))
 
 
 @template