[Spice-devel] [PATCH spice-common] quic: Prevent side effects calling C macros

[Frediano Ziglio]

In some architectures GLib macros to change endianness use the
argument multiple times causing possible side effects.

This happens for instance using Debian SID and MIPS.

This fixes https://gitlab.freedesktop.org/spice/spice-common/issues/1.

Reported-by: Laurent Bigonville <bigon at debian.org>
Tested-by: Laurent Bigonville <bigon at debian.org>
Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 common/quic.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/common/quic.c b/common/quic.c
index 60818c2..c28974e 100644
--- a/common/quic.c
+++ b/common/quic.c
@@ -452,7 +452,8 @@ static inline void read_io_word(Encoder *encoder)
     if (spice_extra_checks) {
         spice_assert(encoder->io_now < encoder->io_end);
     }
-    encoder->io_next_word = GUINT32_FROM_LE(*(encoder->io_now++));
+    encoder->io_next_word = GUINT32_FROM_LE(*(encoder->io_now));
+    encoder->io_now++;
 }
 
 static inline void decode_eatbits(Encoder *encoder, int len)
@@ -585,7 +586,8 @@ static int decode_state_run(Encoder *encoder, CommonState *state)
 
 static inline void init_decode_io(Encoder *encoder)
 {
-    encoder->io_next_word = encoder->io_word = GUINT32_FROM_LE(*(encoder->io_now++));
+    encoder->io_next_word = encoder->io_word = GUINT32_FROM_LE(*(encoder->io_now));
+    encoder->io_now++;
     encoder->io_available_bits = 0;
 }
 
-- 
2.17.1