gh-93418: Fix an assert when an f-string expression is followed by an…

… '=', but no closing brace. (gh-93419) (gh-93423) (cherry picked from commit ee70c70) Co-authored-by: Eric V. Smith <ericvsmith@users.noreply.github.com> Co-authored-by: Eric V. Smith <ericvsmith@users.noreply.github.com>
python · Jun 2, 2022 · 855be47 · 855be47
1 parent 0b7aae8
commit 855be47
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diff --git a/Lib/test/test_fstring.py b/Lib/test/test_fstring.py
@@ -1055,6 +1055,7 @@ def test_mismatched_braces(self):
                              "f'{'",
                              "f'x{<'",  # See bpo-46762.
                              "f'x{>'",
+                             "f'{i='",  # See gh-93418.
                              ])
 
         # But these are just normal strings.

diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-06-01-17-47-40.gh-issue-93418.24dJuc.rst b/Misc/NEWS.d/next/Core and Builtins/2022-06-01-17-47-40.gh-issue-93418.24dJuc.rst
@@ -0,0 +1,2 @@
+Fixed an assert where an f-string has an equal sign '=' following an
+expression, but there's no trailing brace. For example, f"{i=".
diff --git a/Parser/string_parser.c b/Parser/string_parser.c
@@ -740,7 +740,9 @@ fstring_find_expr(Parser *p, const char **str, const char *end, int raw, int rec
         while (Py_ISSPACE(**str)) {
             *str += 1;
         }
-
+        if (*str >= end) {
+            goto unexpected_end_of_string;
+        }
         /* Set *expr_text to the text of the expression. */
         *expr_text = PyUnicode_FromStringAndSize(expr_start, *str-expr_start);
         if (!*expr_text) {