liblzma: Remove common.h include from common/index.h.

common/index.h is needed by liblzma internally and tests. common.h will
include and define many things that are not needed by the tests.

Also, this prevents include order problems because both common.h and
lzma.h define LZMA_API. On most platforms it results only in a warning
but on Windows it would break the build as the definition in common.h
must be used only for building liblzma itself.

src/liblzma/common/index.c

@@ -10,6 +10,7 @@
 //
 ///////////////////////////////////////////////////////////////////////////////
 
+#include "common.h"
 #include "index.h"
 #include "stream_flags_common.h"
 

src/liblzma/common/index.h

@@ -2,6 +2,13 @@
 //
 /// \file       index.h
 /// \brief      Handling of Index
+/// \note       This header file does not include common.h or lzma.h because
+///             this file is needed by both liblzma internally and by the
+///             tests. Including common.h will include and define many things
+///             the tests do not need and prevents issues with header file
+///             include order. This way, if lzma.h or common.h are not
+///             included before this file it will break on every OS instead
+///             of causing more subtle errors.
 //
 //  Author:     Lasse Collin
 //
@@ -13,8 +20,6 @@
 #ifndef LZMA_INDEX_H
 #define LZMA_INDEX_H
 
-#include "common.h"
-
 
 /// Minimum Unpadded Size
 #define UNPADDED_SIZE_MIN LZMA_VLI_C(5)

src/liblzma/common/index_decoder.h

@@ -13,6 +13,7 @@
 #ifndef LZMA_INDEX_DECODER_H
 #define LZMA_INDEX_DECODER_H
 
+#include "common.h"
 #include "index.h"
 
 

src/liblzma/common/stream_buffer_encoder.c

@@ -10,6 +10,7 @@
 //
 ///////////////////////////////////////////////////////////////////////////////
 
+#include "common.h"
 #include "index.h"