Fix: Move LZO compressor from libsquashfs to libcommon

The liblzo2 library is licensed under GPLv2, so it is not possible to
distribute binaries of libsquashfs that link against liblzo2 under
LGPL.

This commit moves the LZO compressor implementation to libcommon,
where this isn't a problem, since the tools themselves are licensed
under GPLv3.

It removes the ability of libsquashfs to read or generate LZO compressed
SquashFS images, but the tools still can.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

2 files changed, 15 insertions, 2 deletions

diff --git a/difftool/Makemodule.am b/difftool/Makemodule.am
index e43f35d..e827a8b 100644
--- a/difftool/Makemodule.am
+++ b/difftool/Makemodule.am
@@ -2,6 +2,6 @@ sqfsdiff_SOURCES = difftool/sqfsdiff.c difftool/sqfsdiff.h difftool/util.c
 sqfsdiff_SOURCES += difftool/compare_dir.c difftool/node_compare.c
 sqfsdiff_SOURCES += difftool/compare_files.c difftool/super.c
 sqfsdiff_SOURCES += difftool/extract.c difftool/options.c
-sqfsdiff_LDADD = libcommon.a libsquashfs.la libutil.la
+sqfsdiff_LDADD = libcommon.a libsquashfs.la libutil.la $(LZO_LIBS)
 
 bin_PROGRAMS += sqfsdiff
diff --git a/difftool/sqfsdiff.c b/difftool/sqfsdiff.c
index 7479938..1c80812 100644
--- a/difftool/sqfsdiff.c
+++ b/difftool/sqfsdiff.c
@@ -22,7 +22,14 @@ static int open_sfqs(sqfs_state_t *state, const char *path)
 		goto fail_file;
 	}
 
-	if (!sqfs_compressor_exists(state->super.compression_id)) {
+	ret = sqfs_compressor_exists(state->super.compression_id);
+
+#ifdef WITH_LZO
+	if (state->super.compression_id == SQFS_COMP_LZO)
+		ret = true;
+#endif
+
+	if (!ret) {
 		fprintf(stderr, "%s: unknown compressor used.\n",
 			path);
 		goto fail_file;
@@ -33,6 +40,12 @@ static int open_sfqs(sqfs_state_t *state, const char *path)
 				    SQFS_COMP_FLAG_UNCOMPRESS);
 
 	state->cmp = sqfs_compressor_create(&state->cfg);
+
+#ifdef WITH_LZO
+	if (state->super.compression_id == SQFS_COMP_LZO && state->cmp == NULL)
+		state->cmp = lzo_compressor_create(&state->cfg);
+#endif
+
 	if (state->cmp == NULL) {
 		fprintf(stderr, "%s: error creating compressor.\n", path);
 		goto fail_file;