From 9ea8f09e9cb2bf8de1d2d3f201a3a01e59c32d8c Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Wed, 7 Sep 2022 11:21:16 +0200
Subject: [PATCH] Fix SIZEOF_OFF_T check for MinGW

---
 libbuild2-autoconf-tests/checks/sizeof/driver.c          | 2 ++
 .../libbuild2/autoconf/checks/SIZEOF_OFF_T.h             | 9 +++++++++
 2 files changed, 11 insertions(+)

diff --git a/libbuild2-autoconf-tests/checks/sizeof/driver.c b/libbuild2-autoconf-tests/checks/sizeof/driver.c
index 0ab4017..91508fc 100644
--- a/libbuild2-autoconf-tests/checks/sizeof/driver.c
+++ b/libbuild2-autoconf-tests/checks/sizeof/driver.c
@@ -20,4 +20,6 @@ main ()
 #ifdef TEST_PTHREAD
   assert (SIZEOF_PTHREAD_T == sizeof (pthread_t));
 #endif
+
+  return 0;
 }
diff --git a/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_OFF_T.h b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_OFF_T.h
index 17f49ef..b94d134 100644
--- a/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_OFF_T.h
+++ b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_OFF_T.h
@@ -8,10 +8,19 @@
  *
  * Note that the _FILE_OFFSET_BITS macro is expected to be defined by the
  * user, for example, on the command line.
+ *
+ * MinGW uses 32-bit off_t both in the 32-bit and 64-bit modes unless forced
+ * with _FILE_OFFSET_BITS.
  */
 
 #ifdef _MSC_VER
 #  define SIZEOF_OFF_T 4
+#elif defined(__MINGW32__)
+#  if defined(_FILE_OFFSET_BITS) && _FILE_OFFSET_BITS == 64
+#    define SIZEOF_OFF_T 8
+#  else
+#    define SIZEOF_OFF_T 4
+#  endif
 #elif (defined(__SIZEOF_SIZE_T__) && __SIZEOF_SIZE_T__ == 8) || \
       (defined(_FILE_OFFSET_BITS) && _FILE_OFFSET_BITS == 64)
 #  define SIZEOF_OFF_T 8