bpo-45582: Fix framework path and bootstrap build (GH-29954)

* Check NS API return values for NULL to prevent segfault in
  ``_bootstrap_python``.
* Set modPathInitialized to 1 so the ``decode_to_dict`` path is used.

Signed-off-by: Christian Heimes <[email protected]>

Author: tiran

Makefile.pre.in

@@ -954,9 +954,9 @@ BOOTSTRAP_HEADERS = \
 
 Programs/_bootstrap_python.o: Programs/_bootstrap_python.c $(BOOTSTRAP_HEADERS) $(PYTHON_HEADERS)
 
-_bootstrap_python: $(LIBRARY_OBJS_OMIT_FROZEN) Programs/_bootstrap_python.o Modules/getpath_bootstrap.o Modules/Setup.local
+_bootstrap_python: $(LIBRARY_OBJS_OMIT_FROZEN) Programs/_bootstrap_python.o Modules/getpath.o Modules/Setup.local
 	$(LINKCC) $(PY_LDFLAGS_NOLTO) -o $@ $(LIBRARY_OBJS_OMIT_FROZEN) \
-		Programs/_bootstrap_python.o Modules/getpath_bootstrap.o $(LIBS) $(MODLIBS) $(SYSLIBS)
+		Programs/_bootstrap_python.o Modules/getpath.o $(LIBS) $(MODLIBS) $(SYSLIBS)
 
 ############################################################################
 # Deepfreeze targets
@@ -1205,18 +1205,6 @@ Modules/getpath.o: $(srcdir)/Modules/getpath.c Python/frozen_modules/getpath.h M
 		-DPLATLIBDIR='"$(PLATLIBDIR)"' \
 		-o $@ $(srcdir)/Modules/getpath.c
 
-# like getpath.o with additional -DPY_BOOTSTRAP_PYTHON=1
-Modules/getpath_bootstrap.o: $(srcdir)/Modules/getpath.c Python/frozen_modules/getpath.h Makefile $(PYTHON_HEADERS)
-	$(CC) -c $(PY_CORE_CFLAGS) -DPYTHONPATH='"$(PYTHONPATH)"' \
-		-DPREFIX='"$(prefix)"' \
-		-DEXEC_PREFIX='"$(exec_prefix)"' \
-		-DVERSION='"$(VERSION)"' \
-		-DVPATH='"$(VPATH)"' \
-		-DPLATLIBDIR='"$(PLATLIBDIR)"' \
-		-DPY_BOOTSTRAP_PYTHON=1 \
-		-o $@ $(srcdir)/Modules/getpath.c
-
-
 Programs/python.o: $(srcdir)/Programs/python.c
 	$(MAINCC) -c $(PY_CORE_CFLAGS) -o $@ $(srcdir)/Programs/python.c
 

Modules/getpath.c

@@ -754,25 +754,28 @@ library_to_dict(PyObject *dict, const char *key)
     if (PyWin_DLLhModule) {
         return winmodule_to_dict(dict, key, PyWin_DLLhModule);
     }
-#elif defined(WITH_NEXT_FRAMEWORK) && !defined(PY_BOOTSTRAP_PYTHON)
-    // _bootstrap_python does not use framework and crashes
+#elif defined(WITH_NEXT_FRAMEWORK)
     static char modPath[MAXPATHLEN + 1];
     static int modPathInitialized = -1;
     if (modPathInitialized < 0) {
-        NSModule pythonModule;
         modPathInitialized = 0;
 
         /* On Mac OS X we have a special case if we're running from a framework.
            This is because the python home should be set relative to the library,
            which is in the framework, not relative to the executable, which may
            be outside of the framework. Except when we're in the build
            directory... */
-        pythonModule = NSModuleForSymbol(NSLookupAndBindSymbol("_Py_Initialize"));
-
-        /* Use dylib functions to find out where the framework was loaded from */
-        const char *path = NSLibraryNameForModule(pythonModule);
-        if (path) {
-            strncpy(modPath, path, MAXPATHLEN);
+        NSSymbol symbol = NSLookupAndBindSymbol("_Py_Initialize");
+        if (symbol != NULL) {
+            NSModule pythonModule = NSModuleForSymbol(symbol);
+            if (pythonModule != NULL) {
+                /* Use dylib functions to find out where the framework was loaded from */
+                const char *path = NSLibraryNameForModule(pythonModule);
+                if (path) {
+                    strncpy(modPath, path, MAXPATHLEN);
+                    modPathInitialized = 1;
+                }
+            }
         }
     }
     if (modPathInitialized > 0) {