From 88066b86c204c0124c269a94249bc5bed1feb788 Mon Sep 17 00:00:00 2001
From: Tzu-ping Chung <uranusjr@gmail.com>
Date: Tue, 24 Jul 2018 20:07:39 +0800
Subject: [PATCH 1/3] Format

---
 pipenv/shells.py | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/pipenv/shells.py b/pipenv/shells.py
index 02c9d951..17a4d871 100644
--- a/pipenv/shells.py
+++ b/pipenv/shells.py
@@ -193,12 +193,18 @@ class CmderPowershell(Shell):
 SHELL_LOOKUP = collections.defaultdict(
     lambda: collections.defaultdict(lambda: Shell),
     {
-        "bash": collections.defaultdict(lambda: Bash),
-        "cmd": collections.defaultdict(lambda: Shell, {"cmder": CmderCommandPrompt}),
-        "powershell": collections.defaultdict(
-            lambda: Shell, {"cmder": CmderPowershell}
+        "bash": collections.defaultdict(
+            lambda: Bash,
+        ),
+        "cmd": collections.defaultdict(
+            lambda: Shell, {"cmder": CmderCommandPrompt},
+        ),
+        "powershell": collections.defaultdict(
+            lambda: Shell, {"cmder": CmderPowershell},
+        ),
+        "pwsh": collections.defaultdict(
+            lambda: Shell, {"cmder": CmderPowershell},
         ),
-        "pwsh": collections.defaultdict(lambda: Shell, {"cmder": CmderPowershell}),
     },
 )
 

From bcce22ffca9a10bbe70515f1484e60f567987922 Mon Sep 17 00:00:00 2001
From: Tzu-ping Chung <uranusjr@gmail.com>
Date: Tue, 24 Jul 2018 20:08:15 +0800
Subject: [PATCH 2/3] Implement MSYS Bash

---
 pipenv/shells.py | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/pipenv/shells.py b/pipenv/shells.py
index 17a4d871..ed2690ac 100644
--- a/pipenv/shells.py
+++ b/pipenv/shells.py
@@ -134,6 +134,9 @@ def _iter_python(venv):
 
 
 class Bash(Shell):
+    def _format_path(self, python):
+        return python.parent.as_posix()
+
     # The usual PATH injection technique does not work with Bash.
     # https://github.com/berdario/pew/issues/58#issuecomment-102182346
     @contextlib.contextmanager
@@ -146,15 +149,25 @@ class Bash(Shell):
                 base_rc_src = 'source "{0}"\n'.format(bashrc_path.as_posix())
                 rcfile.write(base_rc_src)
 
-            export_path = 'export PATH="{0}:$PATH"\n'.format(
-                ":".join(python.parent.as_posix() for python in _iter_python(venv))
-            )
+            export_path = 'export PATH="{0}:$PATH"\n'.format(":".join(
+                self._format_path(python)
+                for python in _iter_python(venv)
+            ))
             rcfile.write(export_path)
             rcfile.flush()
             self.args.extend(["--rcfile", rcfile.name])
             yield
 
 
+class MsysBash(Bash):
+    def _format_path(self, python):
+        s = super(MsysBash, self)._format_path(python)
+        if not python.drive:
+            return s
+        # Convert "C:/something" to "/c/something".
+        return '/{drive}{path}'.format(drive=s[0].lower(), path=s[2:])
+
+
 class CmderEmulatedShell(Shell):
     def fork(self, venv, cwd, args):
         if cwd:
@@ -194,7 +207,7 @@ SHELL_LOOKUP = collections.defaultdict(
     lambda: collections.defaultdict(lambda: Shell),
     {
         "bash": collections.defaultdict(
-            lambda: Bash,
+            lambda: Bash, {"msys": MsysBash},
         ),
         "cmd": collections.defaultdict(
             lambda: Shell, {"cmder": CmderCommandPrompt},

From 4a6f071cfec0690a374f0240e5bfdb21aa1c1137 Mon Sep 17 00:00:00 2001
From: Tzu-ping Chung <uranusjr@gmail.com>
Date: Tue, 24 Jul 2018 20:20:20 +0800
Subject: [PATCH 3/3] Improve emulator detection for multiple values

Running MSYS inside Cmder now returns "cmder,msys", and can look up the
shell correctly.
---
 pipenv/shells.py | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/pipenv/shells.py b/pipenv/shells.py
index ed2690ac..10826f22 100644
--- a/pipenv/shells.py
+++ b/pipenv/shells.py
@@ -223,12 +223,20 @@ SHELL_LOOKUP = collections.defaultdict(
 
 
 def _detect_emulator():
+    keys = []
     if os.environ.get("CMDER_ROOT"):
-        return "cmder"
-    return ""
+        keys.append("cmder")
+    if os.environ.get("MSYSTEM"):
+        keys.append("msys")
+    return ",".join(keys)
 
 
 def choose_shell():
     emulator = PIPENV_EMULATOR.lower() or _detect_emulator()
     type_, command = detect_info()
-    return SHELL_LOOKUP[type_][emulator](command)
+    shell_types = SHELL_LOOKUP[type_]
+    for key in emulator.split(","):
+        key = key.strip().lower()
+        if key in shell_types:
+            return shell_types[key](command)
+    return shell_types[""](command)