Use constraint lines to update requirements

Signed-off-by: Dan Ryan <dan@danryan.co>

pipenv/utils.py

@@ -251,7 +251,7 @@ def actually_resolve_deps(
         # req.as_line() is theoratically the same as dep, but is guaranteed to
         # be normalized. This is safer than passing in dep.
         # TODO: Stop passing dep lines around; just use requirement objects.
-        constraints.append(req.requirement.line)
+        constraints.append(req.constraint_line)
         # extra_constraints = []
 
         if url:
@@ -1220,7 +1220,7 @@ def clean_resolved_dep(dep, is_top_level=False, pipfile_entry=None):
     lockfile = {
         'version': '=={0}'.format(dep['version']),
     }
-    for key in ['hashes', 'index']:
+    for key in ['hashes', 'index', 'extras']:
         if key in dep:
             lockfile[key] = dep[key]
     # In case we lock a uri or a file when the user supplied a path

pipenv/vendor/requirementslib/models/requirements.py

@@ -566,7 +566,7 @@ class Requirement(object):
                 name, extras = _strip_extras(name)
             if version:
                 name = '{0}{1}'.format(name, version)
-            r = NamedRequirement.from_line(name)
+            r = NamedRequirement.from_line(line)
         if extras:
             extras = first(
                 requirements.parse("fakepkg{0}".format(extras_to_string(extras)))
@@ -639,6 +639,12 @@ class Requirement(object):
             line = "{0} {1}".format(line, index_string)
         return line
 
+    @property
+    def constraint_line(self):
+        if self.is_named or self.is_vcs:
+            return self.as_line()
+        return self.req.req.line
+
     def as_pipfile(self):
         good_keys = (
             "hashes",