[3.8] bpo-38234: Backport init path config changes from master (GH-16423)

* bpo-38234: Py_SetPath() uses the program full path (GH-16357)

Py_SetPath() now sets sys.executable to the program full path
(Py_GetProgramFullPath()), rather than to the program name
(Py_GetProgramName()).

Fix also memory leaks in pathconfig_set_from_config().

(cherry picked from commit 1ce152a42eaa917d7763bce93f1e1ca72530d7ca)

* bpo-38234: Add tests for Python init path config (GH-16358)


(cherry picked from commit bb6bf7d342b4503a6227fd209fac934905b6a1aa)

* bpo-38234: test_embed: test pyvenv.cfg and pybuilddir.txt (GH-16366)

Add test_init_pybuilddir() and test_init_pyvenv_cfg() to test_embed
to test pyvenv.cfg and pybuilddir.txt configuration files.

Fix sysconfig._generate_posix_vars(): pybuilddir.txt uses UTF-8
encoding, not ASCII.

(cherry picked from commit 52ad33abbfb6637d74932617c7013bae0ccf6e32)

* bpo-38234: Cleanup getpath.c (GH-16367)

* search_for_prefix() directly calls reduce() if found is greater
  than 0.
* Add calculate_pybuilddir() subfunction.
* search_for_prefix(): add path string buffer for readability.
* Fix some error handling code paths: release resources on error.
* calculate_read_pyenv(): rename tmpbuffer to filename.
* test.pythoninfo now also logs windows.dll_path

(cherry picked from commit 221fd84703c545408bbb4a6e0b58459651331f5c)

* bpo-38234: Fix test_embed pathconfig tests (GH-16390)

bpo-38234: On macOS and FreeBSD, the temporary directory can be
symbolic link. For example, /tmp can be a symbolic link to /var/tmp.
Call realpath() to resolve all symbolic links.

(cherry picked from commit 00508a7407d7d300b487532e2271534b20e378a7)

* bpo-38234: Add test_init_setpath_config() to test_embed (GH-16402)

* Add test_embed.test_init_setpath_config(): test Py_SetPath()
  with PyConfig.
* test_init_setpath() and test_init_setpythonhome() no longer call
  Py_SetProgramName(), but use the default program name.
* _PyPathConfig: isolated, site_import  and base_executable
  fields are now only available on Windows.
* If executable is set explicitly in the configuration, ignore
  calculated base_executable: _PyConfig_InitPathConfig() copies
  executable to base_executable.
* Complete path config documentation.

(cherry picked from commit 8bf39b606ef7b02c0279a80789f3c4824b0da5e9)

* bpo-38234: Complete init config documentation (GH-16404)


(cherry picked from commit 88feaecd46a8f427e30ef7ad8cfcddfe392a2402)

* bpo-38234: Fix test_embed.test_init_setpath_config() on FreeBSD (GH-16406)

Explicitly preinitializes with a Python preconfiguration to avoid
Py_SetPath() implicit preinitialization with a compat
preconfiguration.

Fix also test_init_setpath() and test_init_setpythonhome() on macOS:
use self.test_exe as the executable (and base_executable), rather
than shutil.which('python3').

(cherry picked from commit 49d99f01e6e51acec5ca57a02e857f0796bc418b)

* bpo-38234: Py_Initialize() sets global path configuration (GH-16421)

* Py_InitializeFromConfig() now writes PyConfig path configuration to
  the global path configuration (_Py_path_config).
* Add test_embed.test_get_pathconfig().
* Fix typo in _PyWideStringList_Join().

(cherry picked from commit 12f2f177fc483723406d7917194e7f655a20631b)

1 files changed, 12 insertions, 5 deletions

diff --git a/Include/internal/pycore_pathconfig.h b/Include/internal/pycore_pathconfig.h
index 61b3790..ce75cce 100644
--- a/Include/internal/pycore_pathconfig.h
+++ b/Include/internal/pycore_pathconfig.h
@@ -19,6 +19,7 @@ typedef struct _PyPathConfig {
     wchar_t *program_name;
     /* Set by Py_SetPythonHome() or PYTHONHOME environment variable */
     wchar_t *home;
+#ifdef MS_WINDOWS
     /* isolated and site_import are used to set Py_IsolatedFlag and
        Py_NoSiteFlag flags on Windows in read_pth_file(). These fields
        are ignored when their value are equal to -1 (unset). */
@@ -26,12 +27,18 @@ typedef struct _PyPathConfig {
     int site_import;
     /* Set when a venv is detected */
     wchar_t *base_executable;
+#endif
 } _PyPathConfig;
 
-#define _PyPathConfig_INIT \
-    {.module_search_path = NULL, \
-     .isolated = -1, \
-     .site_import = -1}
+#ifdef MS_WINDOWS
+#  define _PyPathConfig_INIT \
+      {.module_search_path = NULL, \
+       .isolated = -1, \
+       .site_import = -1}
+#else
+#  define _PyPathConfig_INIT \
+      {.module_search_path = NULL}
+#endif
 /* Note: _PyPathConfig_INIT sets other fields to 0/NULL */
 
 PyAPI_DATA(_PyPathConfig) _Py_path_config;
@@ -59,7 +66,7 @@ extern int _Py_FindEnvConfigValue(
 extern wchar_t* _Py_GetDLLPath(void);
 #endif
 
-extern PyStatus _PyPathConfig_Init(void);
+extern PyStatus _PyConfig_WritePathConfig(const PyConfig *config);
 extern void _Py_DumpPathConfig(PyThreadState *tstate);
 
 #ifdef __cplusplus