Handle allocation failures gracefully. Found with failmalloc.

Many (all?) of these could be backported.

Misc/NEWS

@@ -12,6 +12,8 @@ What's New in Python 2.5 release candidate 1?
 Core and builtins
 -----------------
 
+- Fix some potential crashes found with failmalloc.
+
 - Fix warnings reported by Klocwork's static analysis tool.
 
 - Bug #1512814, Fix incorrect lineno's when code within a function

Objects/typeobject.c

@@ -3260,6 +3260,8 @@ PyType_Ready(PyTypeObject *type)
 	if (PyDict_GetItemString(type->tp_dict, "__doc__") == NULL) {
 		if (type->tp_doc != NULL) {
 			PyObject *doc = PyString_FromString(type->tp_doc);
+			if (doc == NULL)
+				goto error;
 			PyDict_SetItemString(type->tp_dict, "__doc__", doc);
 			Py_DECREF(doc);
 		} else {

Objects/unicodeobject.c

@@ -7918,6 +7918,9 @@ void _PyUnicode_Init(void)
     unicode_freelist = NULL;
     unicode_freelist_size = 0;
     unicode_empty = _PyUnicode_New(0);
+    if (!unicode_empty)
+	return;
+
     strcpy(unicode_default_encoding, "ascii");
     for (i = 0; i < 256; i++)
 	unicode_latin1[i] = NULL;

Python/import.c

@@ -116,6 +116,8 @@ _PyImport_Init(void)
 	for (scan = _PyImport_StandardFiletab; scan->suffix != NULL; ++scan)
 		++countS;
 	filetab = PyMem_NEW(struct filedescr, countD + countS + 1);
+	if (filetab == NULL)
+		Py_FatalError("Can't intiialize import file table.");
 	memcpy(filetab, _PyImport_DynLoadFiletab,
 	       countD * sizeof(struct filedescr));
 	memcpy(filetab + countD, _PyImport_StandardFiletab,
@@ -239,8 +241,11 @@ lock_import(void)
 	long me = PyThread_get_thread_ident();
 	if (me == -1)
 		return; /* Too bad */
-	if (import_lock == NULL)
+	if (import_lock == NULL) {
 		import_lock = PyThread_allocate_lock();
+		if (import_lock == NULL)
+			return;  /* Nothing much we can do. */
+	}
 	if (import_lock_thread == me) {
 		import_lock_level++;
 		return;
@@ -259,7 +264,7 @@ static int
 unlock_import(void)
 {
 	long me = PyThread_get_thread_ident();
-	if (me == -1)
+	if (me == -1 || import_lock == NULL)
 		return 0; /* Too bad */
 	if (import_lock_thread != me)
 		return -1;

Python/pystate.c

@@ -63,6 +63,10 @@ PyInterpreterState_New(void)
 
 	if (interp != NULL) {
 		HEAD_INIT();
+#ifdef WITH_THREAD
+		if (head_mutex == NULL)
+			Py_FatalError("Can't initialize threads for interpreter");
+#endif
 		interp->modules = NULL;
 		interp->sysdict = NULL;
 		interp->builtins = NULL;

Python/sysmodule.c

@@ -1137,41 +1137,38 @@ _PySys_Init(void)
 #elif PY_RELEASE_LEVEL == PY_RELEASE_LEVEL_FINAL
 	s = "final";
 #endif
-	PyDict_SetItemString(sysdict, "version_info",
-			     v = Py_BuildValue("iiisi", PY_MAJOR_VERSION,
+
+#define SET_SYS_FROM_STRING(key, value)			\
+	v = value;					\
+	if (v != NULL)					\
+		PyDict_SetItemString(sysdict, key, v);	\
+	Py_XDECREF(v)
+
+	SET_SYS_FROM_STRING("version_info",
+			    Py_BuildValue("iiisi", PY_MAJOR_VERSION,
 					       PY_MINOR_VERSION,
 					       PY_MICRO_VERSION, s,
 					       PY_RELEASE_SERIAL));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "api_version",
-			     v = PyInt_FromLong(PYTHON_API_VERSION));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "copyright",
-			     v = PyString_FromString(Py_GetCopyright()));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "platform",
-			     v = PyString_FromString(Py_GetPlatform()));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "executable",
-			     v = PyString_FromString(Py_GetProgramFullPath()));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "prefix",
-			     v = PyString_FromString(Py_GetPrefix()));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "exec_prefix",
-		   v = PyString_FromString(Py_GetExecPrefix()));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "maxint",
-			     v = PyInt_FromLong(PyInt_GetMax()));
-	Py_XDECREF(v);
+	SET_SYS_FROM_STRING("api_version",
+			    PyInt_FromLong(PYTHON_API_VERSION));
+	SET_SYS_FROM_STRING("copyright",
+			    PyString_FromString(Py_GetCopyright()));
+	SET_SYS_FROM_STRING("platform",
+			    PyString_FromString(Py_GetPlatform()));
+	SET_SYS_FROM_STRING("executable",
+			    PyString_FromString(Py_GetProgramFullPath()));
+	SET_SYS_FROM_STRING("prefix",
+			    PyString_FromString(Py_GetPrefix()));
+	SET_SYS_FROM_STRING("exec_prefix",
+		   	    PyString_FromString(Py_GetExecPrefix()));
+	SET_SYS_FROM_STRING("maxint",
+			    PyInt_FromLong(PyInt_GetMax()));
 #ifdef Py_USING_UNICODE
-	PyDict_SetItemString(sysdict, "maxunicode",
-			     v = PyInt_FromLong(PyUnicode_GetMax()));
-	Py_XDECREF(v);
+	SET_SYS_FROM_STRING("maxunicode",
+			    PyInt_FromLong(PyUnicode_GetMax()));
 #endif
-	PyDict_SetItemString(sysdict, "builtin_module_names",
-		   v = list_builtin_module_names());
-	Py_XDECREF(v);
+	SET_SYS_FROM_STRING("builtin_module_names",
+			    list_builtin_module_names());
 	{
 		/* Assumes that longs are at least 2 bytes long.
 		   Should be safe! */
@@ -1183,18 +1180,16 @@ _PySys_Init(void)
 			value = "big";
 		else
 			value = "little";
-		PyDict_SetItemString(sysdict, "byteorder",
-				     v = PyString_FromString(value));
-		Py_XDECREF(v);
+		SET_SYS_FROM_STRING("byteorder",
+				    PyString_FromString(value));
 	}
 #ifdef MS_COREDLL
-	PyDict_SetItemString(sysdict, "dllhandle",
-			     v = PyLong_FromVoidPtr(PyWin_DLLhModule));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "winver",
-			     v = PyString_FromString(PyWin_DLLVersionString));
-	Py_XDECREF(v);
+	SET_SYS_FROM_STRING("dllhandle",
+			    PyLong_FromVoidPtr(PyWin_DLLhModule));
+	SET_SYS_FROM_STRING("winver",
+			    PyString_FromString(PyWin_DLLVersionString));
 #endif
+#undef SET_SYS_FROM_STRING
 	if (warnoptions == NULL) {
 		warnoptions = PyList_New(0);
 	}