[Spice-devel] [spice-common PATCH 1/3 v2] ppc: Fix lz magic endianess

[Lukas Venhoda]

Commit d39dfbfe changes lz magic to be always treated as LE when encoded.

Runtime conversion from a string to uint32 is storing the magic with the same
endianness on both LE and BE machines. This requires aditional byte swap
when sending magic between LE/BE machines.

Changing lz magic to a constant will ensure, that it will be always stored in
native endianness, and the second byte swap won't be needed.

This commit reverts d39dfbfe changes in lz.c while keeping the rest.
They will be needed in future commit for quic.c
---
Changes since v1:
 - Improved commit log

I didn't revert the patch, because I still need glib.h, but in different file.
---
 common/lz.c        | 4 +---
 common/lz_common.h | 3 ++-
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/common/lz.c b/common/lz.c
index 2350152..d1c4033 100644
--- a/common/lz.c
+++ b/common/lz.c
@@ -47,8 +47,6 @@
 #include <config.h>
 #endif

-#include <glib.h>
-
 #include "spice_common.h"
 #include "lz.h"

@@ -539,7 +537,7 @@ int lz_encode(LzContext *lz, LzImageType type, int width, int height, int top_do
         encoder->usr->error(encoder->usr, "lz encoder reading image segments failed\n");
     }

-    encode_32(encoder, GUINT32_TO_LE(LZ_MAGIC));
+    encode_32(encoder, LZ_MAGIC);
     encode_32(encoder, LZ_VERSION);
     encode_32(encoder, type);
     encode_32(encoder, width);
diff --git a/common/lz_common.h b/common/lz_common.h
index 8d4861b..78df003 100644
--- a/common/lz_common.h
+++ b/common/lz_common.h
@@ -63,7 +63,8 @@ verify(SPICE_N_ELEMENTS(IS_IMAGE_TYPE_RGB) == (LZ_IMAGE_TYPE_A8 + 1));
 verify(SPICE_N_ELEMENTS(PLT_PIXELS_PER_BYTE) == (LZ_IMAGE_TYPE_PLT8 + 1));
 verify(SPICE_N_ELEMENTS(RGB_BYTES_PER_PIXEL) == (LZ_IMAGE_TYPE_A8 + 1));

-#define LZ_MAGIC (*(uint32_t *)"LZ  ")
+/* ASCII "LZ  " */
+#define LZ_MAGIC 0x20205a4c
 #define LZ_VERSION_MAJOR 1U
 #define LZ_VERSION_MINOR 1U
 #define LZ_VERSION ((LZ_VERSION_MAJOR << 16) | (LZ_VERSION_MINOR & 0xffff))
--
2.4.3