From 2c0d9e9409fa8161b781ce9a67f12220d0605703 Mon Sep 17 00:00:00 2001
From: Matt Stafford <wraiyth@gmail.com>
Date: Thu, 6 Jun 2024 13:03:49 +1000
Subject: [PATCH] Add a define to force the use of fallback_file

---
 include/fmt/format-inl.h | 11 +++++++++--
 test/scan.h              |  6 ++++--
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/include/fmt/format-inl.h b/include/fmt/format-inl.h
index 0750e7fcb947..8d07cc672337 100644
--- a/include/fmt/format-inl.h
+++ b/include/fmt/format-inl.h
@@ -1600,14 +1600,21 @@ template <typename F> class fallback_file : public file_base<F> {
   }
 };
 
-template <typename F, FMT_ENABLE_IF(sizeof(F::_p) != 0)>
+#ifndef FMT_USE_FALLBACK_FILE
+#  define FMT_USE_FALLBACK_FILE 1
+#endif
+
+template <typename F,
+          FMT_ENABLE_IF(sizeof(F::_p) != 0 && !FMT_USE_FALLBACK_FILE)>
 auto get_file(F* f, int) -> apple_file<F> {
   return f;
 }
-template <typename F, FMT_ENABLE_IF(sizeof(F::_IO_read_ptr) != 0)>
+template <typename F,
+          FMT_ENABLE_IF(sizeof(F::_IO_read_ptr) != 0 && !FMT_USE_FALLBACK_FILE)>
 inline auto get_file(F* f, int) -> glibc_file<F> {
   return f;
 }
+
 inline auto get_file(FILE* f, ...) -> fallback_file<FILE> { return f; }
 
 using file_ref = decltype(get_file(static_cast<FILE*>(nullptr), 0));
diff --git a/test/scan.h b/test/scan.h
index 15a80356e9c7..1f1cda74ef47 100644
--- a/test/scan.h
+++ b/test/scan.h
@@ -153,11 +153,13 @@ class string_scan_buffer final : public scan_buffer {
 
 class file_scan_buffer final : public scan_buffer {
  private:
-  template <typename F, FMT_ENABLE_IF(sizeof(F::_IO_read_ptr) != 0)>
+  template <typename F, FMT_ENABLE_IF(sizeof(F::_IO_read_ptr) != 0 &&
+                                      !FMT_USE_FALLBACK_FILE)>
   static auto get_file(F* f, int) -> glibc_file<F> {
     return f;
   }
-  template <typename F, FMT_ENABLE_IF(sizeof(F::_p) != 0)>
+  template <typename F,
+            FMT_ENABLE_IF(sizeof(F::_p) != 0 && !FMT_USE_FALLBACK_FILE)>
   static auto get_file(F* f, int) -> apple_file<F> {
     return f;
   }