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bpo-31286, bpo-30024: Fixed stack usage in absolute imports with (#3217) 

binding a submodule to a name.
This commit is contained in:
Serhiy Storchaka 2017-08-29 15:47:44 +03:00 committed by GitHub
parent ba7d736521
commit 265fcc5fc2
2 changed files with 33 additions and 10 deletions
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17
Lib/test/test_import/__init__.py
View File

@ -237,6 +237,23 @@ class ImportTests(unittest.TestCase):
import test.support as y
self.assertIs(y, test.support, y.__name__)
def test_issue31286(self):
# import in a 'finally' block resulted in SystemError
try:
x = ...
finally:
import test.support.script_helper as x
# import in a 'while' loop resulted in stack overflow
i = 0
while i < 10:
import test.support.script_helper as x
i += 1
# import in a 'for' loop resulted in segmentation fault
for i in range(2):
import test.support.script_helper as x
def test_failing_reload(self):
# A failing reload should leave the module object in sys.modules.
source = TESTFN + os.extsep + "py"

26
Python/compile.c
View File

@ -2673,28 +2673,34 @@ compiler_import_as(struct compiler *c, identifier name, identifier asname)
If there is a dot in name, we need to split it and emit a
IMPORT_FROM for each name.
*/
Py_ssize_t dot = PyUnicode_FindChar(name, '.', 0,
PyUnicode_GET_LENGTH(name), 1);
Py_ssize_t len = PyUnicode_GET_LENGTH(name);
Py_ssize_t dot = PyUnicode_FindChar(name, '.', 0, len, 1);
if (dot == -2)
return 0;
if (dot != -1) {
/* Consume the base module name to get the first attribute */
Py_ssize_t pos = dot + 1;
while (dot != -1) {
while (1) {
Py_ssize_t pos = dot + 1;
PyObject *attr;
dot = PyUnicode_FindChar(name, '.', pos,
PyUnicode_GET_LENGTH(name), 1);
dot = PyUnicode_FindChar(name, '.', pos, len, 1);
if (dot == -2)
return 0;
attr = PyUnicode_Substring(name, pos,
(dot != -1) ? dot :
PyUnicode_GET_LENGTH(name));
attr = PyUnicode_Substring(name, pos, (dot != -1) ? dot : len);
if (!attr)
return 0;
ADDOP_O(c, IMPORT_FROM, attr, names);
Py_DECREF(attr);
pos = dot + 1;
if (dot == -1) {
break;
}
ADDOP(c, ROT_TWO);
ADDOP(c, POP_TOP);
}
if (!compiler_nameop(c, asname, Store)) {
return 0;
}
ADDOP(c, POP_TOP);
return 1;
}
return compiler_nameop(c, asname, Store);
}