[PATCH v2] git-compat-util: undefine fileno if defined

[Dan McGregor <dan.mcgregor@usask.ca>]

Commit 8dd2e88a92 ("http: support file handles for HTTP_KEEP_ERROR",
2019-01-10) introduced an implicit assumption that rewind, fileno, and
fflush are functions. At least on FreeBSD fileno is not, and as such
passing a void * failed.

All systems tested (FreeBSD and NetBSD) that define fineo as a macro
also have a function defined. Undefine the macro on these systems so
that the function is used.

Signed-off-by: Dan McGregor <dan.mcgregor@usask.ca>
---
 git-compat-util.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/git-compat-util.h b/git-compat-util.h
index 29a19902aa..b5489bbcf2 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -764,6 +764,15 @@ char *gitstrdup(const char *s);
 extern FILE *git_fopen(const char*, const char*);
 #endif
 
+/* Some systems (the various BSDs for eaxmple) define
+ * fileno as a macro as an optimization. All systems I
+ * know about also define it as a real funcion, so use
+ * the real function to allow passing void *s to fileno.
+ */
+#ifdef fileno
+# undef fileno
+#endif
+
 #ifdef SNPRINTF_RETURNS_BOGUS
 #ifdef snprintf
 #undef snprintf
-- 
2.20.1