From dfb1a19dcf025ef100a14f30568c8d2dc1689026 Mon Sep 17 00:00:00 2001
From: Jeff Tratner <jtratner@counsyl.com>
Date: Thu, 15 Mar 2018 03:53:39 -0700
Subject: [PATCH] Clear pipfile cache when it seems like we might be mutating

---
 pipenv/core.py    |  1 +
 pipenv/project.py | 13 +++++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/pipenv/core.py b/pipenv/core.py
index 00fe1661..3cb8b6cd 100644
--- a/pipenv/core.py
+++ b/pipenv/core.py
@@ -291,6 +291,7 @@ def ensure_pipfile(validate=True, skip_requirements=False):
     if validate and project.virtualenv_exists and not PIPENV_SKIP_VALIDATION:
         # Ensure that Pipfile is using proper casing.
         p = project.parsed_pipfile
+        p.clear_pipfile_cache()
         changed = ensure_proper_casing(pfile=p)
         # Write changes out to disk.
         if changed:
diff --git a/pipenv/project.py b/pipenv/project.py
index 51cfba08..d90ffc12 100644
--- a/pipenv/project.py
+++ b/pipenv/project.py
@@ -294,6 +294,9 @@ class Project(object):
 
     @property
     def parsed_pipfile(self):
+        """Parse Pipfile into a TOMLFile and cache it
+
+        (call clear_pipfile_cache() afterwards if mutating)"""
         # Open the pipfile, read it into memory.
         with open(self.pipfile_location) as f:
             contents = f.read()
@@ -302,9 +305,12 @@ class Project(object):
         if cache_key not in _cache.pipfile_cache:
             parsed = self._parse_pipfile(contents)
             _cache.pipfile_cache[cache_key] = parsed
-        # deepcopy likely unnecessary but why not avoid bugs?
         return _cache.pipfile_cache[cache_key]
 
+    def clear_pipfile_cache(self):
+        """Clear pipfile cache (e.g., so we can mutate parsed pipfile)"""
+        _cache.pipfile_cache.clear()
+
     def _parse_pipfile(self, contents):
         # If any outline tables are present...
         if ('[packages.' in contents) or ('[dev-packages.' in contents):
@@ -338,8 +344,10 @@ class Project(object):
     def _pipfile(self):
         """Pipfile divided by PyPI and external dependencies."""
         pfile = self.parsed_pipfile
+        # mutation time!
+        self.clear_pipfile_cache()
         for section in ('packages', 'dev-packages'):
-            p_section = pfile.get(section, {})
+            p_section = dict(pfile.get(section, {}))
             for key in list(p_section.keys()):
                 # Normalize key name to PEP 423.
                 norm_key = pep423_name(key)
@@ -370,6 +378,7 @@ class Project(object):
             p['pipenv'] = settings
             # Write the changes to disk.
             self.write_toml(p)
+            self.clear_pipfile_cache()
 
     @property
     def _lockfile(self):