Merge branch 'master' into typeshed

jedi/api/environment.py

@@ -153,9 +153,9 @@ def _get_virtual_env_from_var():
     variable is considered to be safe / controlled by the user solely.
     """
     var = os.environ.get('VIRTUAL_ENV')
-    if var is not None:
+    if var:
         if var == sys.prefix:
-            return SameEnvironment()
+            return _try_get_same_env()
 
         try:
             return create_environment(var, safe=False)
@@ -184,9 +184,47 @@ def get_default_environment():
     if virtual_env is not None:
         return virtual_env
 
-    # If no VirtualEnv is found, use the environment we're already
+    return _try_get_same_env()
+
+
+def _try_get_same_env():
+    env = SameEnvironment()
+    if not os.path.basename(env.executable).lower().startswith('python'):
+        # This tries to counter issues with embedding. In some cases (e.g.
+        # VIM's Python Mac/Windows, sys.executable is /foo/bar/vim. This
+        # happens, because for Mac a function called `_NSGetExecutablePath` is
+        # used and for Windows `GetModuleFileNameW`. These are both platform
+        # specific functions. For all other systems sys.executable should be
+        # alright. However here we try to generalize:
+        #
+        # 1. Check if the executable looks like python (heuristic)
+        # 2. In case it's not try to find the executable
+        # 3. In case we don't find it use an interpreter environment.
+        #
+        # The last option will always work, but leads to potential crashes of
+        # Jedi - which is ok, because it happens very rarely and even less,
+        # because the code below should work for most cases.
+        if os.name == 'nt':
+            # The first case would be a virtualenv and the second a normal
+            # Python installation.
+            checks = (r'Scripts\python.exe', 'python.exe')
+        else:
+            # For unix it looks like Python is always in a bin folder.
+            checks = (
+                'bin/python%s.%s' % (sys.version_info[0], sys.version[1]),
+                'bin/python%s' % (sys.version_info[0]),
+                'bin/python',
+            )
+        for check in checks:
+            guess = os.path.join(sys.exec_prefix, check)
+            if os.path.isfile(guess):
+                # Bingo - We think we have our Python.
+                return Environment(guess)
+        # It looks like there is no reasonable Python to be found.
+        return InterpreterEnvironment()
+    # If no virtualenv is found, use the environment we're already
     # using.
-    return SameEnvironment()
+    return env
 
 
 def get_cached_default_environment():

jedi/api/helpers.py

@@ -130,7 +130,10 @@ def get_stack_at_position(grammar, code_lines, module_node, pos):
         p.parse(tokens=tokenize_without_endmarker(code))
     except EndMarkerReached:
         return p.stack
-    raise SystemError("This really shouldn't happen. There's a bug in Jedi.")
+    raise SystemError(
+        "This really shouldn't happen. There's a bug in Jedi:\n%s"
+        % list(tokenize_without_endmarker(code))
+    )
 
 
 def evaluate_goto_definition(evaluator, context, leaf):

jedi/api/project.py

@@ -1,7 +1,7 @@
 import os
 import json
 
-from jedi._compatibility import FileNotFoundError, NotADirectoryError
+from jedi._compatibility import FileNotFoundError, NotADirectoryError, PermissionError
 from jedi.api.environment import SameEnvironment, \
     get_cached_default_environment
 from jedi.api.exceptions import WrongVersion
@@ -151,7 +151,7 @@ def _is_django_path(directory):
     try:
         with open(os.path.join(directory, 'manage.py'), 'rb') as f:
             return b"DJANGO_SETTINGS_MODULE" in f.read()
-    except (FileNotFoundError, NotADirectoryError):
+    except (FileNotFoundError, NotADirectoryError, PermissionError):
         return False
 
     return False
@@ -167,7 +167,7 @@ def get_default_project(path=None):
     for dir in traverse_parents(check, include_current=True):
         try:
             return Project.load(dir)
-        except (FileNotFoundError, NotADirectoryError):
+        except (FileNotFoundError, NotADirectoryError, PermissionError):
             pass
 
         if first_no_init_file is None: