Incorrect SyntaxError location for walrus operator in multi-line conditional expression

Bug report

Bug description:

When using the walrus operator (:=) inside a multi-line conditional expression, Python raises a SyntaxError with the error position pointing to the wrong location.
The caret (^) is shown under the expression body instead of the if clause where the syntax issue actually occurs, making debugging misleading.
The error indicator should instead highlight the if portion (or walrus usage context), not the preceding expression line.

Code

(
    1
    if x := True
    else 2
)

Traceback

File "[REDACTED]", line 2
    1
    ^
SyntaxError: expected 'else' after 'if' expression

It locates error to 1 but it should have located to if x := True (line no. 3)

It does not errors when condition is parenthesized:

(
    1
    if (x := True)
    else 2
)  # output: 1

CPython versions tested on:

3.14

Operating systems tested on:

Linux

Linked PRs

• gh-146305

在 CPython 3.14 上重現多行條件表達式及其加上括號的變體，然後追蹤 walrus 表達式的 parser 或語法錯誤位置處理。完成的標準是：插入符指向 if x := True 所在的行，而加上括號的情況仍能繼續正確解析並回報其結果。