devenv: Do not include system values in --dump

This makes --dump print variables like `FOO=/path:$FOO:/another/path`.

2 files changed, 14 insertions, 13 deletions

diff --git a/mesonbuild/mdevenv.py b/mesonbuild/mdevenv.py
index 7f9b04e..57972ce 100644
--- a/mesonbuild/mdevenv.py
+++ b/mesonbuild/mdevenv.py
@@ -6,7 +6,7 @@ import itertools
 
 from pathlib import Path
 from . import build, minstall, dependencies
-from .mesonlib import MesonException, is_windows, setup_vsenv, OptionKey, quote_arg, get_wine_shortpath
+from .mesonlib import MesonException, is_windows, setup_vsenv, OptionKey, get_wine_shortpath
 from . import mlog
 
 import typing as T
@@ -47,15 +47,15 @@ def reduce_winepath(env: T.Dict[str, str]) -> None:
     env['WINEPATH'] = get_wine_shortpath([winecmd], winepath.split(';'))
     mlog.log('Meson detected wine and has set WINEPATH accordingly')
 
-def get_env(b: build.Build) -> T.Tuple[T.Dict[str, str], T.Set[str]]:
+def get_env(b: build.Build, dump: bool) -> T.Tuple[T.Dict[str, str], T.Set[str]]:
     extra_env = build.EnvironmentVariables()
     extra_env.set('MESON_DEVENV', ['1'])
     extra_env.set('MESON_PROJECT_NAME', [b.project_name])
 
-    env = os.environ.copy()
+    env = {} if dump else os.environ.copy()
     varnames = set()
     for i in itertools.chain(b.devenv, {extra_env}):
-        env = i.get_env(env)
+        env = i.get_env(env, dump)
         varnames |= i.get_names()
 
     reduce_winepath(env)
@@ -141,12 +141,12 @@ def run(options: argparse.Namespace) -> int:
     b = build.load(options.builddir)
     workdir = options.workdir or options.builddir
 
-    devenv, varnames = get_env(b)
+    devenv, varnames = get_env(b, options.dump)
     if options.dump:
         if options.devcmd:
             raise MesonException('--dump option does not allow running other command.')
         for name in varnames:
-            print(f'{name}={quote_arg(devenv[name])}')
+            print(f'{name}="{devenv[name]}"')
             print(f'export {name}')
         return 0
 
diff --git a/mesonbuild/utils/core.py b/mesonbuild/utils/core.py
index ed413ca..5450cdc 100644
--- a/mesonbuild/utils/core.py
+++ b/mesonbuild/utils/core.py
@@ -119,23 +119,24 @@ class EnvironmentVariables(HoldableObject):
         self.envvars.append((self._prepend, name, values, separator))
 
     @staticmethod
-    def _set(env: T.Dict[str, str], name: str, values: T.List[str], separator: str) -> str:
+    def _set(env: T.Dict[str, str], name: str, values: T.List[str], separator: str, default_value: T.Optional[str]) -> str:
         return separator.join(values)
 
     @staticmethod
-    def _append(env: T.Dict[str, str], name: str, values: T.List[str], separator: str) -> str:
-        curr = env.get(name)
+    def _append(env: T.Dict[str, str], name: str, values: T.List[str], separator: str, default_value: T.Optional[str]) -> str:
+        curr = env.get(name, default_value)
         return separator.join(values if curr is None else [curr] + values)
 
     @staticmethod
-    def _prepend(env: T.Dict[str, str], name: str, values: T.List[str], separator: str) -> str:
-        curr = env.get(name)
+    def _prepend(env: T.Dict[str, str], name: str, values: T.List[str], separator: str, default_value: T.Optional[str]) -> str:
+        curr = env.get(name, default_value)
         return separator.join(values if curr is None else values + [curr])
 
-    def get_env(self, full_env: T.MutableMapping[str, str]) -> T.Dict[str, str]:
+    def get_env(self, full_env: T.MutableMapping[str, str], dump: bool = False) -> T.Dict[str, str]:
         env = full_env.copy()
         for method, name, values, separator in self.envvars:
-            env[name] = method(env, name, values, separator)
+            default_value = f'${name}' if dump else None
+            env[name] = method(env, name, values, separator, default_value)
         return env