[3.12] gh-105908: fix `barry_as_FLUFL` future import (GH-105909) (#105930)

(cherry picked from commit 28187a9c4f95affe50fd37e0db0db177e2b9c2e9)

Co-authored-by: Crowthebird <78076854+thatbirdguythatuknownot@users.noreply.github.com>

1 files changed, 10 insertions, 6 deletions

diff --git a/Python/compile.c b/Python/compile.c
index f593e95..a8d0016 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -510,8 +510,10 @@ static PyCodeObject *optimize_and_assemble(struct compiler *, int addNone);
 
 static int
 compiler_setup(struct compiler *c, mod_ty mod, PyObject *filename,
-               PyCompilerFlags flags, int optimize, PyArena *arena)
+               PyCompilerFlags *flags, int optimize, PyArena *arena)
 {
+    PyCompilerFlags local_flags = _PyCompilerFlags_INIT;
+
     c->c_const_cache = PyDict_New();
     if (!c->c_const_cache) {
         return ERROR;
@@ -527,10 +529,13 @@ compiler_setup(struct compiler *c, mod_ty mod, PyObject *filename,
     if (!_PyFuture_FromAST(mod, filename, &c->c_future)) {
         return ERROR;
     }
-    int merged = c->c_future.ff_features | flags.cf_flags;
+    if (!flags) {
+        flags = &local_flags;
+    }
+    int merged = c->c_future.ff_features | flags->cf_flags;
     c->c_future.ff_features = merged;
-    flags.cf_flags = merged;
-    c->c_flags = flags;
+    flags->cf_flags = merged;
+    c->c_flags = *flags;
     c->c_optimize = (optimize == -1) ? _Py_GetConfig()->optimization_level : optimize;
     c->c_nestlevel = 0;
 
@@ -555,12 +560,11 @@ static struct compiler*
 new_compiler(mod_ty mod, PyObject *filename, PyCompilerFlags *pflags,
              int optimize, PyArena *arena)
 {
-    PyCompilerFlags flags = pflags ? *pflags : _PyCompilerFlags_INIT;
     struct compiler *c = PyMem_Calloc(1, sizeof(struct compiler));
     if (c == NULL) {
         return NULL;
     }
-    if (compiler_setup(c, mod, filename, flags, optimize, arena) < 0) {
+    if (compiler_setup(c, mod, filename, pflags, optimize, arena) < 0) {
         compiler_free(c);
         return NULL;
     }