libdpkg: Switch dpkg_lzma_strerror() to use struct io_lzma

Instead of passing the dpkg_stream_action enum, pass the io_lzma struct,
so that we can use other members if needed.

lib/dpkg/compress.c

@@ -483,9 +483,22 @@ enum dpkg_stream_status {
 	DPKG_STREAM_FILTER	= DPKG_STREAM_COMPRESS | DPKG_STREAM_DECOMPRESS,
 };
 
+struct io_lzma {
+	const char *desc;
+
+	struct compress_params *params;
+
+	enum dpkg_stream_status status;
+	lzma_action action;
+
+	void (*init)(struct io_lzma *io, lzma_stream *s);
+	int (*code)(struct io_lzma *io, lzma_stream *s);
+	void (*done)(struct io_lzma *io, lzma_stream *s);
+};
+
 /* XXX: liblzma does not expose error messages. */
 static const char *
-dpkg_lzma_strerror(lzma_ret code, enum dpkg_stream_status status)
+dpkg_lzma_strerror(struct io_lzma *io, lzma_ret code)
 {
 	const char *const impossible = _("internal error (bug)");
 
@@ -493,29 +506,29 @@ dpkg_lzma_strerror(lzma_ret code, enum dpkg_stream_status status)
 	case LZMA_MEM_ERROR:
 		return strerror(ENOMEM);
 	case LZMA_MEMLIMIT_ERROR:
-		if (status & DPKG_STREAM_RUN)
+		if (io->status & DPKG_STREAM_RUN)
 			return _("memory usage limit reached");
 		return impossible;
 	case LZMA_OPTIONS_ERROR:
-		if (status == (DPKG_STREAM_INIT | DPKG_STREAM_COMPRESS))
+		if (io->status == (DPKG_STREAM_INIT | DPKG_STREAM_COMPRESS))
 			return _("unsupported compression preset");
-		if (status == (DPKG_STREAM_RUN | DPKG_STREAM_DECOMPRESS))
+		if (io->status == (DPKG_STREAM_RUN | DPKG_STREAM_DECOMPRESS))
 			return _("unsupported options in file header");
 		return impossible;
 	case LZMA_DATA_ERROR:
-		if (status & DPKG_STREAM_RUN)
+		if (io->status & DPKG_STREAM_RUN)
 			return _("compressed data is corrupt");
 		return impossible;
 	case LZMA_BUF_ERROR:
-		if (status & DPKG_STREAM_RUN)
+		if (io->status & DPKG_STREAM_RUN)
 			return _("unexpected end of input");
 		return impossible;
 	case LZMA_FORMAT_ERROR:
-		if (status == (DPKG_STREAM_RUN | DPKG_STREAM_DECOMPRESS))
+		if (io->status == (DPKG_STREAM_RUN | DPKG_STREAM_DECOMPRESS))
 			return _("file format not recognized");
 		return impossible;
 	case LZMA_UNSUPPORTED_CHECK:
-		if (status == (DPKG_STREAM_INIT | DPKG_STREAM_COMPRESS))
+		if (io->status == (DPKG_STREAM_INIT | DPKG_STREAM_COMPRESS))
 			return _("unsupported type of integrity check");
 		return impossible;
 	default:
@@ -523,18 +536,6 @@ dpkg_lzma_strerror(lzma_ret code, enum dpkg_stream_status status)
 	}
 }
 
-struct io_lzma {
-	const char *desc;
-
-	struct compress_params *params;
-	enum dpkg_stream_status status;
-	lzma_action action;
-
-	void (*init)(struct io_lzma *io, lzma_stream *s);
-	int (*code)(struct io_lzma *io, lzma_stream *s);
-	void (*done)(struct io_lzma *io, lzma_stream *s);
-};
-
 static void
 filter_lzma(struct io_lzma *io, int fd_in, int fd_out)
 {
@@ -592,7 +593,7 @@ static void DPKG_ATTR_NORET
 filter_lzma_error(struct io_lzma *io, lzma_ret ret)
 {
 	ohshit(_("%s: lzma error: %s"), io->desc,
-	       dpkg_lzma_strerror(ret, io->status));
+	       dpkg_lzma_strerror(io, ret));
 }
 
 #ifdef HAVE_LZMA_MT_ENCODER