From db25269cb8266d6672c3f5b3dbd569cdf74af6e3 Mon Sep 17 00:00:00 2001
From: Crowthebird <78076854+thatbirdguythatuknownot@users.noreply.github.com>
Date: Sun, 20 Nov 2022 09:26:58 +0800
Subject: [PATCH 1/2] implement logic + remove redundancy

Note on "remove redundancy": in `compiler_joined_str()`, replace all further references of `asdl_seq_LEN(e->v.JoinedStr.values)` with `value_count`.
---
 Python/compile.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/Python/compile.c b/Python/compile.c
index 9226bc233ead74..894c15ce33c0e3 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -4926,12 +4926,16 @@ compiler_joined_str(struct compiler *c, expr_ty e)
 {
     location loc = LOC(e);
     Py_ssize_t value_count = asdl_seq_LEN(e->v.JoinedStr.values);
-    if (value_count > STACK_USE_GUIDELINE) {
+    if (!value_count || value_count > STACK_USE_GUIDELINE) {
+        /* Also handle empty f-strings here */
         _Py_DECLARE_STR(empty, "");
         ADDOP_LOAD_CONST_NEW(c, loc, Py_NewRef(&_Py_STR(empty)));
+        if (!value_count) {
+            return 0;
+        }
         ADDOP_NAME(c, loc, LOAD_METHOD, &_Py_ID(join), names);
         ADDOP_I(c, loc, BUILD_LIST, 0);
-        for (Py_ssize_t i = 0; i < asdl_seq_LEN(e->v.JoinedStr.values); i++) {
+        for (Py_ssize_t i = 0; i < value_count; i++) {
             VISIT(c, expr, asdl_seq_GET(e->v.JoinedStr.values, i));
             ADDOP_I(c, loc, LIST_APPEND, 1);
         }
@@ -4939,8 +4943,8 @@ compiler_joined_str(struct compiler *c, expr_ty e)
     }
     else {
         VISIT_SEQ(c, expr, e->v.JoinedStr.values);
-        if (asdl_seq_LEN(e->v.JoinedStr.values) != 1) {
-            ADDOP_I(c, loc, BUILD_STRING, asdl_seq_LEN(e->v.JoinedStr.values));
+        if (value_count != 1) {
+            ADDOP_I(c, loc, BUILD_STRING, value_count);
         }
     }
     return 1;

From c226f0e4db9d40851dfe636e11c391a340dcb036 Mon Sep 17 00:00:00 2001
From: Crowthebird <78076854+thatbirdguythatuknownot@users.noreply.github.com>
Date: Sun, 20 Nov 2022 09:54:24 +0800
Subject: [PATCH 2/2] returned fail instead of success

---
 Python/compile.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Python/compile.c b/Python/compile.c
index 894c15ce33c0e3..f9afd44c701283 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -4931,7 +4931,7 @@ compiler_joined_str(struct compiler *c, expr_ty e)
         _Py_DECLARE_STR(empty, "");
         ADDOP_LOAD_CONST_NEW(c, loc, Py_NewRef(&_Py_STR(empty)));
         if (!value_count) {
-            return 0;
+            return 1;
         }
         ADDOP_NAME(c, loc, LOAD_METHOD, &_Py_ID(join), names);
         ADDOP_I(c, loc, BUILD_LIST, 0);