[Python-checkins] bpo-44143: Fix crash in the parser when raising tokenizer errors with an exception set (GH-26144)

[pablogsal]

https://github.com/python/cpython/commit/80b089179fa798c8ceaab2ff699c82499b2fcacd
commit: 80b089179fa798c8ceaab2ff699c82499b2fcacd
branch: main
author: Pablo Galindo <Pablogsal at gmail.com>
committer: pablogsal <Pablogsal at gmail.com>
date: 2021-05-15T17:58:02+01:00
summary:

bpo-44143: Fix crash in the parser when raising tokenizer errors with an exception set (GH-26144)

files:
A Misc/NEWS.d/next/Core and Builtins/2021-05-15-17-30-57.bpo-44143.7UTS6H.rst
M Lib/test/test_exceptions.py
M Parser/pegen.c

diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index 1fe479fbe83092..aefdd7b769f289 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -242,6 +242,7 @@ def baz():
             """, 9, 24)
         check("pass\npass\npass\n(1+)\npass\npass\npass", 4, 4)
         check("(1+)", 1, 4)
+        check("[interesting\nfoo()\n", 1, 1)
 
         # Errors thrown by symtable.c
         check('x = [(yield i) for i in range(3)]', 1, 5)
diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-05-15-17-30-57.bpo-44143.7UTS6H.rst b/Misc/NEWS.d/next/Core and Builtins/2021-05-15-17-30-57.bpo-44143.7UTS6H.rst
new file mode 100644
index 00000000000000..a4e88e55723e4d
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2021-05-15-17-30-57.bpo-44143.7UTS6H.rst	
@@ -0,0 +1,2 @@
+Fixed a crash in the parser that manifest when raising tokenizer errors when
+an existing exception was present. Patch by Pablo Galindo.
diff --git a/Parser/pegen.c b/Parser/pegen.c
index 6080cec1489ed8..c2f25402ca4e13 100644
--- a/Parser/pegen.c
+++ b/Parser/pegen.c
@@ -1259,6 +1259,7 @@ _PyPegen_check_tokenizer_errors(Parser *p) {
                 if (p->tok->level != 0) {
                     int error_lineno = p->tok->parenlinenostack[p->tok->level-1];
                     if (current_err_line > error_lineno) {
+                        PyErr_Clear();
                         raise_unclosed_parentheses_error(p);
                         return -1;
                     }