[3.5] bpo-29778: Ensure python3.dll is loaded from correct locations when Python is embedded (GH-21297) by zooba · Pull Request #21377 · python/cpython

Expand Up @@ -93,7 +93,6 @@
static wchar_t prefix[MAXPATHLEN+1]; static wchar_t progpath[MAXPATHLEN+1]; static wchar_t dllpath[MAXPATHLEN+1]; static wchar_t *module_search_path = NULL;

Expand Down Expand Up @@ -122,6 +121,46 @@ reduce(wchar_t *dir) dir[i] = '\0'; }
static int change_ext(wchar_t *dest, const wchar_t *src, const wchar_t *ext) { if (src && src != dest) { size_t src_len = wcsnlen_s(src, MAXPATHLEN+1); size_t i = src_len; if (i >= MAXPATHLEN+1) { Py_FatalError("buffer overflow in getpathp.c's reduce()"); }
while (i > 0 && src[i] != '.' && !is_sep(src[i])) --i;
if (i == 0) { dest[0] = '\0'; return -1; }
if (is_sep(src[i])) { i = src_len; }
if (wcsncpy_s(dest, MAXPATHLEN+1, src, i)) { dest[0] = '\0'; return -1; } } else { wchar_t *s = wcsrchr(dest, L'.'); if (s) { s[0] = '\0'; } }
if (wcscat_s(dest, MAXPATHLEN+1, ext)) { dest[0] = '\0'; return -1; }
return 0; }
static int exists(wchar_t *filename) Expand Down Expand Up @@ -214,6 +253,20 @@ search_for_prefix(wchar_t *argv0_path, wchar_t *landmark) return 0; }

static int get_dllpath(wchar_t *dllpath) { #ifdef Py_ENABLE_SHARED extern HANDLE PyWin_DLLhModule; if (PyWin_DLLhModule && GetModuleFileNameW(PyWin_DLLhModule, dllpath, MAXPATHLEN)) { return 0; } #endif return -1; }

#ifdef MS_WINDOWS #ifdef Py_ENABLE_SHARED
Expand Down Expand Up @@ -378,19 +431,8 @@ get_progpath(void) wchar_t *path = _wgetenv(L"PATH"); wchar_t *prog = Py_GetProgramName();
#ifdef MS_WINDOWS #ifdef Py_ENABLE_SHARED extern HANDLE PyWin_DLLhModule; /* static init of progpath ensures final char remains \0 */ if (PyWin_DLLhModule) if (!GetModuleFileNameW(PyWin_DLLhModule, dllpath, MAXPATHLEN)) dllpath[0] = 0; #else dllpath[0] = 0; #endif if (GetModuleFileNameW(NULL, progpath, MAXPATHLEN)) return; #endif if (prog == NULL || *prog == '\0') prog = L"python";
Expand Down Expand Up @@ -578,14 +620,10 @@ calculate_path(void)
#ifdef MS_WINDOWS /* Calculate zip archive path from DLL or exe path */ if (wcscpy_s(zip_path, MAXPATHLEN+1, dllpath[0] ? dllpath : progpath)) /* exceeded buffer length - ignore zip_path */ zip_path[0] = '\0'; else { wchar_t *dot = wcsrchr(zip_path, '.'); if (!dot || wcscpy_s(dot, MAXPATHLEN+1 - (dot - zip_path), L".zip")) /* exceeded buffer length - ignore zip_path */ zip_path[0] = L'\0'; if (!get_dllpath(zip_path)) { change_ext(zip_path, zip_path, L".zip"); } else { change_ext(zip_path, progpath, L".zip"); }
skiphome = pythonhome==NULL ? 0 : 1; Expand Down Expand Up @@ -768,8 +806,6 @@ calculate_path(void) }

/* External interface */
void Py_SetPath(const wchar_t *path) { Expand Down Expand Up @@ -830,25 +866,39 @@ int _Py_CheckPython3() { wchar_t py3path[MAXPATHLEN+1]; wchar_t *s; if (python3_checked) if (python3_checked) { return hPython3 != NULL; } python3_checked = 1;
/* If there is a python3.dll next to the python3y.dll, assume this is a build tree; use that DLL */ wcscpy(py3path, dllpath); s = wcsrchr(py3path, L'\\'); if (!s) s = py3path; wcscpy(s, L"\\python3.dll"); hPython3 = LoadLibraryExW(py3path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH); if (hPython3 != NULL) return 1; use that DLL */ if (!get_dllpath(py3path)) { reduce(py3path); join(py3path, PY3_DLLNAME); hPython3 = LoadLibraryExW(py3path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH); if (hPython3 != NULL) { return 1; } }
/* Check sys.prefix\DLLs\python3.dll */ /* If we can locate python3.dll in our application dir, use that DLL */ wcscpy(py3path, Py_GetPrefix()); wcscat(py3path, L"\\DLLs\\python3.dll"); hPython3 = LoadLibraryExW(py3path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH); if (py3path[0]) { join(py3path, PY3_DLLNAME); hPython3 = LoadLibraryExW(py3path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH); if (hPython3 != NULL) { return 1; } }
/* For back-compat, also search {sys.prefix}\DLLs, though that has not been a normal install layout for a while */ wcscpy(py3path, Py_GetPrefix()); if (py3path[0]) { join(py3path, L"DLLs\\" PY3_DLLNAME); hPython3 = LoadLibraryExW(py3path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH); } return hPython3 != NULL; }