[3.7] bpo-34977: Use venv redirector instead of original python.exe on Windows (GH-11029)

1 files changed, 7 insertions, 1 deletions

diff --git a/PC/getpathp.c b/PC/getpathp.c
index 599b41b1ef..1b553d53af 100644
--- a/PC/getpathp.c
+++ b/PC/getpathp.c
@@ -536,10 +536,16 @@ static _PyInitError
 get_program_full_path(const _PyCoreConfig *core_config,
                       PyCalculatePath *calculate, _PyPathConfig *config)
 {
+    const wchar_t *pyvenv_launcher;
     wchar_t program_full_path[MAXPATHLEN+1];
     memset(program_full_path, 0, sizeof(program_full_path));
 
-    if (!GetModuleFileNameW(NULL, program_full_path, MAXPATHLEN)) {
+    /* The launcher may need to force the executable path to a
+     * different environment, so override it here. */
+    pyvenv_launcher = _wgetenv(L"__PYVENV_LAUNCHER__");
+    if (pyvenv_launcher && pyvenv_launcher[0]) {
+        wcscpy_s(program_full_path, MAXPATHLEN+1, pyvenv_launcher);
+    } else if (!GetModuleFileNameW(NULL, program_full_path, MAXPATHLEN)) {
         /* GetModuleFileName should never fail when passed NULL */
         return _Py_INIT_ERR("Cannot determine program path");
     }