The index name in Pipfile.lock don't update until lock again

[frostming]

Issue description

As title

Expected result

After changing the source name in Pipfile and do lock, the index names in Pipfile.lock should update to reflect the change.

Actual result

I have to do lock twice to make the index names change.

Steps to replicate

Given this Pipfile:

[[source]]
url = "https://pypi.org/simple"
name = "pypi"
verify_ssl = true

[dev-packages]

[packages]
six = "*"

1. $ pipenv lock, the index name in Pipfile.lock is pypi
2. Change the source name in Pipfile to test
3. $ pipenv lock, the index name in Pipfile.lock is still pypi
4. $ pipenv lock, the index name in Pipfile.lock is test

---

Please run $ pipenv --support, and paste the results here. Don't put backticks (`) around it! The output already contains Markdown formatting.

$ pipenv --support

Pipenv version: '2018.11.26'

Pipenv location: 'c:\\users\\frostming\\.local\\venvs\\pipenv\\lib\\site-packages\\pipenv'

Python location: 'c:\\users\\frostming\\.local\\venvs\\pipenv\\scripts\\python.exe'

Python installations found:

• 3.7.2: D:\Programs\Python\Python37-32\python.exe
• 2.7: D:\Programs\Python\Python27\python.exe

PEP 508 Information:

{'implementation_name': 'cpython',
 'implementation_version': '3.7.2',
 'os_name': 'nt',
 'platform_machine': 'AMD64',
 'platform_python_implementation': 'CPython',
 'platform_release': '10',
 'platform_system': 'Windows',
 'platform_version': '10.0.15063',
 'python_full_version': '3.7.2',
 'python_version': '3.7',
 'sys_platform': 'win32'}

System environment variables:

• ALIASES
• ALLUSERSPROFILE
• ANSICON
• ANSICON_DEF
• APPDATA
• ARCHITECTURE
• ARCHITECTURE_BITS
• CCALL
• CEXEC
• CMDER_ALIASES
• CMDER_CLINK
• CMDER_CONFIGURED
• CMDER_INIT_END
• CMDER_INIT_START
• CMDER_ROOT
• CMDER_SHELL
• CMDER_USER_FLAGS
• COMMONPROGRAMFILES
• COMMONPROGRAMFILES(X86)
• COMMONPROGRAMW6432
• COMPUTERNAME
• COMSPEC
• CONEMUANSI
• CONEMUANSILOG
• CONEMUARGS
• CONEMUARGS2
• CONEMUBACKHWND
• CONEMUBASEDIR
• CONEMUBASEDIRSHORT
• CONEMUBUILD
• CONEMUCFGDIR
• CONEMUCONFIG
• CONEMUDIR
• CONEMUDRAWHWND
• CONEMUDRIVE
• CONEMUHOOKS
• CONEMUHWND
• CONEMUPALETTE
• CONEMUPID
• CONEMUSERVERPID
• CONEMUTASK
• CONEMUWORKDIR
• CONEMUWORKDRIVE
• DEBUG_OUTPUT
• FAST_INIT
• FEFLAGNAME
• FPS_BROWSER_APP_PROFILE_STRING
• FPS_BROWSER_USER_PROFILE_STRING
• GIT_INSTALL_ROOT
• HOME
• HOMEDRIVE
• HOMEPATH
• HTTPS_PROXY
• JAVA_HOME
• LANG
• LIB_BASE
• LIB_CONSOLE
• LIB_GIT
• LIB_PATH
• LIB_PROFILE
• LOCALAPPDATA
• LOGONSERVER
• MAX_DEPTH
• NUMBER_OF_PROCESSORS
• ONEDRIVE
• OS
• PATH
• PATHEXT
• PLINK_PROTOCOL
• PROCESSOR_ARCHITECTURE
• PROCESSOR_ARCHITEW6432
• PROCESSOR_IDENTIFIER
• PROCESSOR_LEVEL
• PROCESSOR_REVISION
• PROGRAMDATA
• PROGRAMFILES
• PROGRAMFILES(X86)
• PROGRAMW6432
• PROMPT
• PSMODULEPATH
• PUBLIC
• PYTHONIOENCODING
• SESSIONNAME
• SVN_SSH
• SYSTEMDRIVE
• SYSTEMROOT
• TEMP
• TERM
• TIME_INIT
• TMP
• USERDNSDOMAIN
• USERDOMAIN
• USERDOMAIN_ROAMINGPROFILE
• USERNAME
• USERPROFILE
• USER_ALIASES
• VERBOSE_OUTPUT
• WINDIR
• PIP_DISABLE_PIP_VERSION_CHECK
• PYTHONDONTWRITEBYTECODE
• PIP_SHIMS_BASE_MODULE
• PIP_PYTHON_PATH
• PYTHONFINDER_IGNORE_UNSUPPORTED

Pipenv–specific environment variables:

Debug–specific environment variables:

• PATH: D:\Programs\Cmder\bin;D:\Programs\Cmder\vendor\bin;D:\Programs\Cmder\vendor\conemu-maximus5\ConEmu\Scripts;D:\Programs\Cmder\vendor\conemu-maximus5;D:\Programs\Cmder\vendor\conemu-maximus5\ConEmu;C:\Program Files (x86)\Intel\iCLS Client\;C:\Program Files\Intel\iCLS Client\;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;D:\Programs\Git\cmd;D:\Programs\TortoiseSVN\bin;D:\Programs\Gpg4win\..\GnuPG\bin;C:\Users\frostming\scoop\apps\nodejs\current\bin;C:\Users\frostming\scoop\apps\nodejs\current;C:\Users\frostming\scoop\shims;C:\Users\frostming\.poetry\bin;C:\Users\frostming\AppData\Local\Programs\Python\Launcher\;D:\Programs\Python\Python37-32\Scripts\;D:\Programs\Python\Python37-32\;C:\Users\frostming\AppData\Local\Microsoft\WindowsApps;C:\Users\frostming\.local\bin;D:\Programs\Microsoft VS Code\bin;C:\Users\frostming\AppData\Local\Yarn\bin;D:\Programs\GnuWin32\bin;D:\Programs\heroku\bin;D:\Programs\Java\apache-maven-3.2.5\bin;C:\Users\frostming\AppData\Local\Programs\PythonUp\scripts;C:\Users\frostming\AppData\Local\Programs\PythonUp\cmd;C:\Users\frostming\AppData\Local\hyper\app-2.1.0\resources\bin;C:\Users\frostming\AppData\Local\Pandoc\;D:\Programs\Git\cmd;D:\Programs\Git\mingw64\bin;D:\Programs\Git\usr\bin;D:\Programs\Cmder
• LANG: zh_CN.UTF-8

---

Contents of Pipfile ('D:\Workspace\mynew\Pipfile'):

[[source]]
url = "https://pypi.org/simple"
name = "test"
verify_ssl = true

[dev-packages]

[packages]
six = "*"

[requires]
python_version = "3.7"

Contents of Pipfile.lock ('D:\Workspace\mynew\Pipfile.lock'):

{
    "_meta": {
        "hash": {
            "sha256": "e3852270a09909b8c247bc177dd80f077b663fbf52120707da322c57e794d43e"
        },
        "pipfile-spec": 6,
        "requires": {
            "python_version": "3.7"
        },
        "sources": [
            {
                "name": "test",
                "url": "https://pypi.org/simple",
                "verify_ssl": true
            }
        ]
    },
    "default": {
        "six": {
            "hashes": [
                "sha256:3350809f0555b11f552448330d0b52d5f24c91a322ea4a15ef22629740f3761c",
                "sha256:d16a0141ec1a18405cd4ce8b4613101da75da0e9a7aec5bdd4fa804d0e0eba73"
            ],
            "index": "test",
            "version": "==1.12.0"
        }
    },
    "develop": {}
}